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  <xsd:element id="wtm_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySalesOrSettlements" name="FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySalesOrSettlements" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
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  <xsd:element id="wtm_FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringAndNonRecurringBasisTableTextBlock" name="FairValueOfAssetsAndLiabilitiesMeasuredOnRecurringAndNonRecurringBasisTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
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  <xsd:element id="wtm_InvestmentsInUnconsolidatedAffiliatesAtQuotedMarketPrice" name="InvestmentsInUnconsolidatedAffiliatesAtQuotedMarketPrice" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
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  <xsd:element id="wtm_LiabilitiesHeldForSale" name="LiabilitiesHeldForSale" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
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  <xsd:element id="wtm_LossFromDilutiveEffectResultingFromDividendAndIssuanceOfRestrictedShares" name="LossFromDilutiveEffectResultingFromDividendAndIssuanceOfRestrictedShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="wtm_LossandLAEReserveandNetLossandLAEDevelopmentTableTextBlock" name="LossandLAEReserveandNetLossandLAEDevelopmentTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="wtm_MarineTreatyMember" name="MarineTreatyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_MarineTreatyPerOccurrenceMember" name="MarineTreatyPerOccurrenceMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="wtm_MatchingContributionDomain" name="MatchingContributionDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_MediaAlphaBankFacilityMember" name="MediaAlphaBankFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="wtm_MembersSurplusContributionsMember" name="MembersSurplusContributionsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element id="wtm_MinimumPercentageOfVariationFromExpectedPriceRequiredToTreatPricesOfInvestmentsProvidedByPricingServicesAsOutliers" name="MinimumPercentageOfVariationFromExpectedPriceRequiredToTreatPricesOfInvestmentsProvidedByPricingServicesAsOutliers" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_MinimumVariationFromExpectedPriceRequiredToTreatPricesOfInvestmentsProvidedByPricingServicesAsOutliers" name="MinimumVariationFromExpectedPriceRequiredToTreatPricesOfInvestmentsProvidedByPricingServicesAsOutliers" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="wtm_MultipleOfGaapBookValueMember" name="MultipleOfGaapBookValueMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_MultipleofEBITDAMember" name="MultipleofEBITDAMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_MunicipalBondContract" name="MunicipalBondContract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_MunicipalBondInsurancePolicyTextBlock" name="MunicipalBondInsurancePolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_MunicipalBondOutstandingInterest" name="MunicipalBondOutstandingInterest" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="wtm_MunicipalBondOutstandingPrincipal" name="MunicipalBondOutstandingPrincipal" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="wtm_NetAcquisitionsOfPropertyAndEquipment" name="NetAcquisitionsOfPropertyAndEquipment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_NetChangeInInvestmentsRelatedToPurchasesAndSalesOfConsolidatedunconsolidatedAffiliates" name="NetChangeInInvestmentsRelatedToPurchasesAndSalesOfConsolidatedunconsolidatedAffiliates" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_NetExposureOnFairValueOfOverCounterDerivativeInstruments" name="NetExposureOnFairValueOfOverCounterDerivativeInstruments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="wtm_NetInvestmentIncomeSurplusNotes" name="NetInvestmentIncomeSurplusNotes" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_NetOperatingLossesInLuxembourgSubsidiariesMember" name="NetOperatingLossesInLuxembourgSubsidiariesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_NetOperatingLossesinIsraelSubsidiariesMember" name="NetOperatingLossesinIsraelSubsidiariesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_NetOperatingLossesinNetherlandsSubsidiariesMemberMember" name="NetOperatingLossesinNetherlandsSubsidiariesMemberMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_NetRealizedAndUnrealizedGainLossAndForeignCurrencyGainLossOnTradingSecuritiesNetOfTax" name="NetRealizedAndUnrealizedGainLossAndForeignCurrencyGainLossOnTradingSecuritiesNetOfTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_NetRealizedGainLossandForeignCurrencyGainLossonTradingSecuritiesNetofTax" name="NetRealizedGainLossandForeignCurrencyGainLossonTradingSecuritiesNetofTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_NetRealizedandUnrealizedGainLossonTradingSecuritiesNetofTax" name="NetRealizedandUnrealizedGainLossonTradingSecuritiesNetofTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_NetUnrealizedGainLossAndForeignCurrencyGainLossOnTradingSecuritiesNetOfTax" name="NetUnrealizedGainLossAndForeignCurrencyGainLossOnTradingSecuritiesNetOfTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_NetUnrealizedGainLossandForeignCurrencyGainLossonTradingSecurities" name="NetUnrealizedGainLossandForeignCurrencyGainLossonTradingSecurities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_NetUnrealizedGainLossandForeignCurrencyGainLossonTradingSecuritiesTax" name="NetUnrealizedGainLossandForeignCurrencyGainLossonTradingSecuritiesTax" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="wtm_NetUnrestrictedCashShortTermAndFixedMaturityInvestments" name="NetUnrestrictedCashShortTermAndFixedMaturityInvestments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="wtm_NetunrealizedgainslossesofunconsolidatedaffiliatesMember" name="NetunrealizedgainslossesofunconsolidatedaffiliatesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_NoexpirationdateMember" name="NoexpirationdateMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_NomuraMember" name="NomuraMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_NonAgencyCommercialMortgageBackedSecuritiesInterestRateAndSeniorityTableTextBlock" name="NonAgencyCommercialMortgageBackedSecuritiesInterestRateAndSeniorityTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_NonAgencyResidentialMortgageBackedSecuritiesCreditQualityIndicatorsAndSeniorityTableTextBlock" name="NonAgencyResidentialMortgageBackedSecuritiesCreditQualityIndicatorsAndSeniorityTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_NonAgencyResidentialMortgageMember" name="NonAgencyResidentialMortgageMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_NoncashorPartNoncashDistributionReceived" name="NoncashorPartNoncashDistributionReceived" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="wtm_NoncontrollingInterestPolicyTextBlock" name="NoncontrollingInterestPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_NoninsuranceMember" name="NoninsuranceMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_NordeaBankFinlandMember" name="NordeaBankFinlandMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_NumberOfInstallmentsInWhichSharesVest" name="NumberOfInstallmentsInWhichSharesVest" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_NumberOfInvestments" name="NumberOfInvestments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_NumberOfInvestmentsHeld" name="NumberOfInvestmentsHeld" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_NumberOfInvestmentsWithSignificantUnobseravbleInputs" name="NumberOfInvestmentsWithSignificantUnobseravbleInputs" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_NumberOfTrust" name="NumberOfTrust" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_Numberofyearsofchangeininterestrate" name="Numberofyearsofchangeininterestrate" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_Numberofyearstoreceiveportionofrevenue" name="Numberofyearstoreceiveportionofrevenue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OakumBayCapitalMember" name="OakumBayCapitalMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_OffesttingAssetsAndLiabilitiesTableTextBlock" name="OffesttingAssetsAndLiabilitiesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OneBeaconBankFacilityMember" name="OneBeaconBankFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OneBeaconEmployeeStockOwnershipPlanMember" name="OneBeaconEmployeeStockOwnershipPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OneBeaconHoldingsIncMember" name="OneBeaconHoldingsIncMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OneBeaconInsuranceCompanyMember" name="OneBeaconInsuranceCompanyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OneBeaconInsuranceGroupLtdMember" name="OneBeaconInsuranceGroupLtdMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OneTitleMember" name="OneTitleMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OnebeaconMember" name="OnebeaconMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OnebeaconRunoffMember" name="OnebeaconRunoffMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OperatingAndCapitalLossCarryforwardsDeferredTaxAssetsNetAbstract" name="OperatingAndCapitalLossCarryforwardsDeferredTaxAssetsNetAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OperatingAndCapitalLossCarryforwardsLineItems" name="OperatingAndCapitalLossCarryforwardsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OperatingandCapitalLossCarryforwardMember" name="OperatingandCapitalLossCarryforwardMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OptionpricingmethodMember" name="OptionpricingmethodMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherBenefitPlansAbstract" name="OtherBenefitPlansAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherCasualtyBusinessMember" name="OtherCasualtyBusinessMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_OtherComprehensiveIncomeLossEquityinUnrealizedGainsLossesfromInvestmentsinUnconsolidatedAffiliates" name="OtherComprehensiveIncomeLossEquityinUnrealizedGainsLossesfromInvestmentsinUnconsolidatedAffiliates" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_OtherComprehensiveIncomeLossEquityinUnrealizedGainsLossesfromInvestmentsinUnconsolidatedAffiliatesTaxEffect" name="OtherComprehensiveIncomeLossEquityinUnrealizedGainsLossesfromInvestmentsinUnconsolidatedAffiliatesTaxEffect" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_OtherComprehensiveIncomeReversalofaccumulatedothercomprehensiveincomeUnrealizedGainLossonInvestmentsNetofTaxPeriodIncreaseDecrease" name="OtherComprehensiveIncomeReversalofaccumulatedothercomprehensiveincomeUnrealizedGainLossonInvestmentsNetofTaxPeriodIncreaseDecrease" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherDebtMember" name="OtherDebtMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_OtherInvestmentIncomeAndGainLossOnInvestments" name="OtherInvestmentIncomeAndGainLossOnInvestments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherLongTermInvestmentsExcludingEquityMethodInvestmentsMember" name="OtherLongTermInvestmentsExcludingEquityMethodInvestmentsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_OtherLongTermInvestmentsLargestSingleInvestment" name="OtherLongTermInvestmentsLargestSingleInvestment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="wtm_OtherLongTermInvestmentsPolicyPolicyTextBlock" name="OtherLongTermInvestmentsPolicyPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_OtherNonCashReconcilingItemsIncludingShareBasedCompensationShareAmortization" name="OtherNonCashReconcilingItemsIncludingShareBasedCompensationShareAmortization" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherOperationsMember" name="OtherOperationsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherSectorMember" name="OtherSectorMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherSignificantTransactionNameDomain" name="OtherSignificantTransactionNameDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherSignificantTransactionsByUniqueDescriptionAxis" name="OtherSignificantTransactionsByUniqueDescriptionAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherSignificantTransactionsTable" name="OtherSignificantTransactionsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherSpecialtyIndustriesMember" name="OtherSpecialtyIndustriesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherSpecialtyProductsMember" name="OtherSpecialtyProductsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_OtherStandardPoorsRatingMember" name="OtherStandardPoorsRatingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_Outstandingredemptions" name="Outstandingredemptions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="wtm_OwnerhsipPercentageOfCommonEquity" name="OwnerhsipPercentageOfCommonEquity" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="wtm_ParValueMember" name="ParValueMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ParValuetoFairValueReconciliationofSurplusNotesTableTextBlock" name="ParValuetoFairValueReconciliationofSurplusNotesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PariPassuSurplusNoteMember" name="PariPassuSurplusNoteMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PartnershipinvestmentsMember" name="PartnershipinvestmentsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PassportCardMember" name="PassportCardMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PaymentforSubsidiarySharesRetired" name="PaymentforSubsidiarySharesRetired" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_PaymentsToAcquireTradingCommonEquitySecurities" name="PaymentsToAcquireTradingCommonEquitySecurities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_PaymentsToAcquireTradingFixedMaturityAndConvertibleFixedMaturityInvestments" name="PaymentsToAcquireTradingFixedMaturityAndConvertibleFixedMaturityInvestments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_Paymentsofdistributionsfromsubsidiariestoshareholders" name="Paymentsofdistributionsfromsubsidiariestoshareholders" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PensionliabilityandotheraccumulatedcomprehensiveitemsMember" name="PensionliabilityandotheraccumulatedcomprehensiveitemsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PenteliaCapitalManagementMember" name="PenteliaCapitalManagementMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PercentageOfCertifiedLossesRequiredToBeSharedByFederalGovernmentSubjectToTerrorismRiskInsuranceAct" name="PercentageOfCertifiedLossesRequiredToBeSharedByFederalGovernmentSubjectToTerrorismRiskInsuranceAct" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PercentageOfCommonSharesOutstandingOwnedByPlans" name="PercentageOfCommonSharesOutstandingOwnedByPlans" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PercentageOfFeesInExcessOfSpecifiedAmountOfRevenueChargeablePursuantToRevenueSharingAgreementWithRelatedParty" name="PercentageOfFeesInExcessOfSpecifiedAmountOfRevenueChargeablePursuantToRevenueSharingAgreementWithRelatedParty" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_PercentageOfInvestmentsRecordedAtFairValue" name="PercentageOfInvestmentsRecordedAtFairValue" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PercentageOfLikelihoodForRealizationOfBenefitUponUltimateSettlement" name="PercentageOfLikelihoodForRealizationOfBenefitUponUltimateSettlement" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PercentageOfParValueOfPolicyReinsured" name="PercentageOfParValueOfPolicyReinsured" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_PercentageOfQuotaShareReinsuranceAgreement" name="PercentageOfQuotaShareReinsuranceAgreement" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PercentageofPremiums" name="PercentageofPremiums" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_Percentageofcommonshareholdersequity" name="Percentageofcommonshareholdersequity" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_Percentageoflossreservedevelopmentretained" name="Percentageoflossreservedevelopmentretained" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_Percentageofperformancesharesearned" name="Percentageofperformancesharesearned" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_Percentofgrossprofit" name="Percentofgrossprofit" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PermanentDifferencesMember" name="PermanentDifferencesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PreferenceSharesFloatingRateOfDividendAmountInExcessOfLibor" name="PreferenceSharesFloatingRateOfDividendAmountInExcessOfLibor" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PreferenceSharesReferenceRateForDividend" name="PreferenceSharesReferenceRateForDividend" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PreferredEquitySecuritiesMember" name="PreferredEquitySecuritiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PreferredStockRedemptionBasisSpreadOnTreasuryIssueRate" name="PreferredStockRedemptionBasisSpreadOnTreasuryIssueRate" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PremiumsEarnedGross" name="PremiumsEarnedGross" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_PretaxOperatingResultsTableTextBlock" name="PretaxOperatingResultsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PriorWTMBankFacilityMember" name="PriorWTMBankFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PrivateEquityEnergyInfrastructureAndServicesMember" name="PrivateEquityEnergyInfrastructureAndServicesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PrivateEquityFundsManufacturingAndIndustrialMember" name="PrivateEquityFundsManufacturingAndIndustrialMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PrivateEquityFundsRemainingLockUpPeriodAxis" name="PrivateEquityFundsRemainingLockUpPeriodAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PrivateEquityHealthcareMember" name="PrivateEquityHealthcareMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PrivateEquityInsuranceMember" name="PrivateEquityInsuranceMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PrivateEquityLockUpPeriodTableTextBlock" name="PrivateEquityLockUpPeriodTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PrivateEquityMultiSectorMember" name="PrivateEquityMultiSectorMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PrivateEquitySecondariesMember" name="PrivateEquitySecondariesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ProceedsFromMaturitiesOfTradingFixedMaturityAndConvertibleFixedMaturityInvestments" name="ProceedsFromMaturitiesOfTradingFixedMaturityAndConvertibleFixedMaturityInvestments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="wtm_ProceedsFromSaleOfTradingCommonEquitySecurities" name="ProceedsFromSaleOfTradingCommonEquitySecurities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
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  <xsd:element id="wtm_ProceedsFromSubsidiaries" name="ProceedsFromSubsidiaries" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="wtm_ProceedsFromTribuneCommonStock" name="ProceedsFromTribuneCommonStock" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="wtm_ProceedsfromSaleandMaturityofTradingSecuritiesHeldforinvestmentExcludingShortTermSecurities" name="ProceedsfromSaleandMaturityofTradingSecuritiesHeldforinvestmentExcludingShortTermSecurities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="wtm_Proceedsrelatedfromterminationofagreement" name="Proceedsrelatedfromterminationofagreement" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
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  <xsd:element abstract="true" id="wtm_ProjectedSurrenderAssumptionMember" name="ProjectedSurrenderAssumptionMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PropertyCatastropheProgramMember" name="PropertyCatastropheProgramMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="wtm_PropertyPerRiskActsofTerrorismMember" name="PropertyPerRiskActsofTerrorismMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PropertyPerRiskReinsuranceProgramMember" name="PropertyPerRiskReinsuranceProgramMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PropertyPerRiskTreatyMember" name="PropertyPerRiskTreatyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_ProspectorFundsMember" name="ProspectorFundsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_ProspectorOffshoreFundLtdMember" name="ProspectorOffshoreFundLtdMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_ProspectorTurtleFundMember" name="ProspectorTurtleFundMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_PurchaseAccountingMember" name="PurchaseAccountingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_PurchaseofSurplusNotes" name="PurchaseofSurplusNotes" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="wtm_QuoteLabMember" name="QuoteLabMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_RBCScore" name="RBCScore" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_RangeOfPerformanceCycleFrom2010To2012Member" name="RangeOfPerformanceCycleFrom2010To2012Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_RangeOfPerformanceCycleFrom2011To2013Member" name="RangeOfPerformanceCycleFrom2011To2013Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_RangeOfPerformanceCycleFrom2012To2014Member" name="RangeOfPerformanceCycleFrom2012To2014Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_RangeOfPerformanceCycleFrom2013To2015Member" name="RangeOfPerformanceCycleFrom2013To2015Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="wtm_RecentTransactionThreeMember" name="RecentTransactionThreeMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_RecentTransactionTwoMember" name="RecentTransactionTwoMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="wtm_RegulatoryApprovalMember" name="RegulatoryApprovalMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_ReinsuranceContractByNatureAxis" name="ReinsuranceContractByNatureAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="wtm_ReinsuranceTypeandTierIdentifierAxis" name="ReinsuranceTypeandTierIdentifierAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
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  <xsd:element id="wtm_RelatedPartyOwnerhshipPercentage" name="RelatedPartyOwnerhshipPercentage" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_RelatedPartyTransactionIncentiveFeesFromTransactionsWithRelatedParty" name="RelatedPartyTransactionIncentiveFeesFromTransactionsWithRelatedParty" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="wtm_RepaymentOfDebtFromSubsidiaries" name="RepaymentOfDebtFromSubsidiaries" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_RepurchasedforEmployeeBenefitPlansMember" name="RepurchasedforEmployeeBenefitPlansMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_ResidentialNonprimeFinancingReceivableMember" name="ResidentialNonprimeFinancingReceivableMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_RestrictedShareCliffVestingInJanuary2016Member" name="RestrictedShareCliffVestingInJanuary2016Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_RestrictedShareCliffVestinginJanuary2017Member" name="RestrictedShareCliffVestinginJanuary2017Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_RestrictedShareCliffVestinginJanuary2018Member" name="RestrictedShareCliffVestinginJanuary2018Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_RetainedPercentageRelatingToCertifiedLossesRequiredtobeSharedbyFederalGovernmentSubjecttoTerrorismRiskInsuranceAct" name="RetainedPercentageRelatingToCertifiedLossesRequiredtobeSharedbyFederalGovernmentSubjecttoTerrorismRiskInsuranceAct" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_RevenuesharingagreementMember" name="RevenuesharingagreementMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_RightToElectDirectorsOnBoardNumber" name="RightToElectDirectorsOnBoardNumber" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_RiskFreeRate" name="RiskFreeRate" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="wtm_RoyalBankOfScotlandMember" name="RoyalBankOfScotlandMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_SAndPCreditRatings" name="SAndPCreditRatings" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="wtm_SIGPreferenceSharesMember" name="SIGPreferenceSharesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleOfAccumulatedBenefitObligationsLessThanFairValueOfPlanAssetsTableTextBlock" name="ScheduleOfAccumulatedBenefitObligationsLessThanFairValueOfPlanAssetsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleOfChangesInInvestmentsInUnconsolidatedAffiliatesTableTextBlock" name="ScheduleOfChangesInInvestmentsInUnconsolidatedAffiliatesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleOfDiscontinuedOperationsCalculationOfNumeratorAndDenominatorInEarningsPerShareTableTextBlock" name="ScheduleOfDiscontinuedOperationsCalculationOfNumeratorAndDenominatorInEarningsPerShareTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_ScheduleOfExchangeRateUsedForMostSignificantTransactionsTable" name="ScheduleOfExchangeRateUsedForMostSignificantTransactionsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
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  <xsd:element id="wtm_ScheduleOfMunicipalGuaranteeInsuredObligationsTableTextBlock" name="ScheduleOfMunicipalGuaranteeInsuredObligationsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleOfNetOperatingAndCapitalLossCarryforwardsByExpirationDateAndDeferredTaxAssetTableTextBlock" name="ScheduleOfNetOperatingAndCapitalLossCarryforwardsByExpirationDateAndDeferredTaxAssetTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleOfNonvestedPerformanceShareActivityTableTextBlock" name="ScheduleOfNonvestedPerformanceShareActivityTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleOfNonvestedRestrictedStockActivityTableTextBlock" name="ScheduleOfNonvestedRestrictedStockActivityTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleOfPerformanceSharesOutstandingAndAccruedExpenseByPerformanceCycleUnderIncentivePlanTableTextBlock" name="ScheduleOfPerformanceSharesOutstandingAndAccruedExpenseByPerformanceCycleUnderIncentivePlanTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleOfRealizedAndUnrealizedGainLossOnInvestmentsTableTextBlock" name="ScheduleOfRealizedAndUnrealizedGainLossOnInvestmentsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleOfSecurityIssuanceYearsOfInvestmentsInMortgageBackedSecuritiesIssuedByPrivateEnterprisesTableTextBlock" name="ScheduleOfSecurityIssuanceYearsOfInvestmentsInMortgageBackedSecuritiesIssuedByPrivateEnterprisesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleOfSelectedBalanceSheetDataBySegmentTableTextBlock" name="ScheduleOfSelectedBalanceSheetDataBySegmentTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleillustratingthevaluationadjustmentsbetweenparandfairvalueTableTextBlock" name="ScheduleillustratingthevaluationadjustmentsbetweenparandfairvalueTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ScheduleofcollateralTableTextBlock" name="ScheduleofcollateralTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecondCasualtyExcessofLossMember" name="SecondCasualtyExcessofLossMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecondThresholdLimitMember" name="SecondThresholdLimitMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedIn2005Member" name="SecuritiesIssuedIn2005Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedIn2006Member" name="SecuritiesIssuedIn2006Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedIn2007Member" name="SecuritiesIssuedIn2007Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedIn2008Member" name="SecuritiesIssuedIn2008Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedIn2009Member" name="SecuritiesIssuedIn2009Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedIn2010Member" name="SecuritiesIssuedIn2010Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedIn2011Member" name="SecuritiesIssuedIn2011Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedIn2012Member" name="SecuritiesIssuedIn2012Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedIn2013Member" name="SecuritiesIssuedIn2013Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedin2004Member" name="SecuritiesIssuedin2004Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedin2014Member" name="SecuritiesIssuedin2014Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecuritiesIssuedin2015Member" name="SecuritiesIssuedin2015Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_SecuritiesOutsideVarianceThresholds" name="SecuritiesOutsideVarianceThresholds" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecurityIssuanceYearAxis" name="SecurityIssuanceYearAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SecurityIssuanceYearDomain" name="SecurityIssuanceYearDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SellerPrioritySurplusNoteMember" name="SellerPrioritySurplusNoteMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_SeniorMember" name="SeniorMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_ShareBasedCompensationArrangementByPerformanceSharesAwardPerformanceCycleAxis" name="ShareBasedCompensationArrangementByPerformanceSharesAwardPerformanceCycleAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_ShareBasedCompensationArrangementByPerformanceSharesAwardPerformanceCycleDomain" name="ShareBasedCompensationArrangementByPerformanceSharesAwardPerformanceCycleDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAmountsPaidInPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAmountsPaidInPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="wtm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAssumedForfeitures" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAssumedForfeitures" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAssumedForfeituresAmount" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAssumedForfeituresAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="wtm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantDateFairValueRollForward" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantDateFairValueRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberBeforeForfeitures" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberBeforeForfeitures" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant" />
  <xsd:element id="wtm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReductionInGrantTotal" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsReductionInGrantTotal" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
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  <xsd:element abstract="true" id="wtm_WindandearthquakeMember" name="WindandearthquakeMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_WindandfloodMember" name="WindandfloodMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_WorkersCompensationMember" name="WorkersCompensationMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_WtmBankFacilityMember" name="WtmBankFacilityMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="wtm_YearOneMember" name="YearOneMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_YearsPerformanceShareswillbeForfeitedPeriod" name="YearsPerformanceShareswillbeForfeitedPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="wtm_Yearsofinterestratecap" name="Yearsofinterestratecap" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
</xsd:schema>
