Third Party Reinsurance (Tables)

6 Months Ended

Jun. 30, 2012

The following table provides a listing of OneBeacon’s top reinsurers, excluding industry pools and associations, based upon recoverable amounts, the percentage of total paid and unpaid reinsurance recoverables and the reinsurer’s A.M Best Company, Inc. (“A.M. Best”) rating.



Top Reinsurers (Millions)	Balance at June 30, 2012		% of Total		A.M. Best Rating ⁽¹⁾
National Indemnity Company and General Reinsurance Corporation ⁽²⁾	$	1,475.1	66	%	A++
Hanover Insurance Company	74.8		3	%	A
Tokio Marine and Nichido Fire⁽³⁾	54.4		2	%	A++
Tower Insurance Company	26.2		1	%	A-
Munich Reinsurance America	25.5		1	%	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 $198.3 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 $28.3 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 Sirius's top reinsurers

The following table provides a listing of Sirius Group’s top reinsurers based upon recoverable amounts, the percentage of total paid and unpaid reinsurance recoverables and the reinsurers’ A.M. Best ratings.



Top Reinsurers (Millions)	Balance at June 30, 2012		% of Total		A.M. Best Rating ⁽¹⁾	% Collateralized
General Reinsurance Corporation	$	42.3	12	%	A++	1	%
Swiss Re Group	39.7		12	%	A+	5	%
Olympus⁽²⁾	29.5		9	%	NR-5	100	%
Lloyds of London⁽³⁾	25.2		7	%	A	7	%
Michigan Catastrophic Claims Association ⁽⁴⁾	14.6		4	%	N/A	—	%

⁽¹⁾A.M. Best ratings as detailed above are: “A++” (Superior, which is the highest of fifteen financial strength ratings), “A+” (Superior, which is the second highest of fifteen financial strength ratings), “A” (Excellent, which is the third highest of fifteen financial strength ratings) and “NR-5” (Not formally followed).

⁽²⁾Non-U.S. insurance entity. The balance is fully collateralized through funds held, letters of credit or trust agreements.

⁽³⁾Represents the total of reinsurance recoverables due to Sirius Group from all Lloyds Syndicates.

⁽⁴⁾ Michigan Catastrophic Claims Association ("MCCA") is a non-profit unincorporated association to which every insurance company that sells automobile coverage in Michigan is required to be a member. A.M. Best does not rate MCCA. Sirius Group acquired its recoverable from MCCA in the acquisition of Stockbridge.