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Third Party Reinsurance (Tables) | 6 Months Ended
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Jun. 30, 2011
Third Party Reinsurance |
Listing of OneBeacon's top reinsurers |
Top Reinsurers (Millions) |  | Balance at June 30, 2011 |  | % of Total |  | A.M. Best Rating(1) |
National Indemnity Company and General Reinsurance Corporation (2) |  | $ | 1,491.4 |  | 74 | % | A++ |
Hanover Insurance Company |  | 113.6 |  | 6 | % | A |
Tokio Marine and Nichido Fire (3) |  | 64.2 |  | 3 | % | A++ |
Tower Insurance Company |  | 62.3 |  | 3 | % | A- |
Munich Reinsurance America |  | 32.5 |  | 2 | % | A+ |
(1) A.M. Best ratings as detailed above are: “A++” (Superior, which is the highest of fifteen ratings), “A+” (Superior, which is the second highest of fifteen ratings), “A” (Excellent, which is the third highest of fifteen ratings), and “A-” (Excellent, which is the fourth highest of fifteen ratings). (2) Includes $193.5 of Third Party Recoverables (as defined below), which NICO (as defined below) would pay under the terms of the NICO Cover (as defined below) if they are unable to collect from third party reinsurers. (3) Includes $37.1 of reinsurance recoverables from various third party reinsurers that are guaranteed by Tokio Marine and Nichido Fire under the terms of a 100% quota share reinsurance agreement between Houston General Insurance Company and Tokio Marine and Nichido Fire.
Listing of White Mountains Re's top reinsurers |
Top Reinsurers (Millions) |  | Balance at June 30, 2011 |  | % of Total |  | A.M. Best Rating (1) |  | % Collateralized |
Olympus (2) |  | $ | 44.8 |  | 11 | % | NR-5 |  | 100 | %
Lloyds of London(3) |  | 43.7 |  | 11 | % | A |  | 3 | %
General Reinsurance Corporation |  | 43.3 |  | 11 | % | A++ |  | 2 | %
Swiss Re Group |  | 39.5 |  | 10 | % | A |  | 4 | %
Michigan Catastrophic Claims Association |  | 15.2 |  | 4 | % | N/A(4) |  | — | %
(1) A.M. Best ratings as detailed above are: “NR-5” (Not formally followed), “A++” (Superior, which is the highest of fifteen ratings), and “A” (Excellent, which is the third highest of fifteen ratings). (2) Non-U.S. insurance entity. Balances are fully collateralized through funds held, letters of credit or trust agreements. (3) Represents the total of reinsurance recoverables due to White Mountains Re from all Lloyds Syndicates. (4) Michigan Catastrophic Claims Association (“MCCA”) is a non-profit unincorporated association of which every insurance company that sells automobile coverage in Michigan is required to be a member. A.M. Best does not rate MCCA. White Mountains Re acquired its recoverable from MCCA pursuant to its acquisition of Stockbridge.

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- Definition Tabular disclosure of the top five reinsurers that have assumed business from OneBeacon (excluding industry pools and associations) based on the amount recoverable from each reinsurer. The disclosure for each reinsurer also includes the amount recoverable as a percentage of OneBeacon's consolidated reinsurance recoverables and the A.M Best Company, Inc. ("A.M. Best") rating. + Details
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- Definition Tabular disclosure of the top five reinsurers that have assumed business from White Mountains Re based on the amount recoverable from each reinsurer. The disclosure for each reinsurer also includes the amount recoverable as a percentage of White Mountains Re's total reinsurance recoverables, the A.M Best Company, Inc. ("A.M. Best") rating and the percentage of the amount recoverable that is collateralized. + Details
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