Exhibit 21
SUBSIDIARIES OF THE REGISTRANT
AS OF DECEMBER 31, 2010
FULL NAME OF SUBSIDIARY |
| PLACE OF INCORPORATION |
ANSWER FINANCIAL INC. |
| DELAWARE, USA |
CENTRAL NATIONAL INSURANCE COMPANY OF OMAHA |
| NEBRASKA, USA |
ESURANCE INSURANCE SERVICES, INC. |
| DELAWARE, USA |
ESURANCE HOLDINGS BERMUDA LTD. |
| BERMUDA |
ESURANCE HOLDINGS INC. |
| DELAWARE, USA |
ESURANCE INSURANCE COMPANY |
| WISCONSIN, USA |
WHITE MOUNTAINS HOLDING COMPANY, INC. |
| NEW YORK, USA |
WHITE MOUNTAINS REINSURANCE COMPANY OF AMERICA |
| NEW YORK, USA |
FUND AMERICAN HOLDINGS AB |
| SWEDEN |
GUILFORD HOLDINGS, INC. |
| DELAWARE, USA |
HOMELAND INSURANCE COMPANY OF NEW YORK |
| NEW YORK, USA |
INSURANCE ANSWER CENTER, LLC |
| DELAWARE, USA |
LONE TREE HOLDINGS LTD. |
| BERMUDA |
LONE TREE INSURANCE GROUP LTD. |
| BERMUDA |
MILL SHARES HOLDINGS BERMUDA LIMITED |
| BERMUDA |
MORTGAGE ANSWER CENTER, INC. |
| DELAWARE, USA |
ONEBEACON U.S. ENTERPRISES HOLDINGS, INC. |
| DELAWARE, USA |
ONEBEACON U.S. FINANCIAL SERVICES, INC. |
| DELAWARE, USA |
ONEBEACON U.S. HOLDINGS, INC. |
| DELAWARE, USA |
ONEBEACON AMERICA INSURANCE COMPANY |
| MASSACHUSETTS, USA |
ONEBEACON HOLDINGS (GIBRALTAR) LIMITED |
| GIBRALTAR |
ONEBEACON HOLDINGS (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
ONEBEACON INSURANCE COMPANY |
| PENNSYLVANIA, USA |
ONEBEACON INSURANCE GROUP LLC |
| DELAWARE, USA |
ONEBEACON INSURANCE GROUP LTD. |
| BERMUDA |
ONEBEACON INVESTMENT (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
PSC HOLDINGS LTD. |
| BERMUDA |
PENNSYLVANIA GENERAL INSURANCE COMPANY |
| PENNSYLVANIA, USA |
SCANDINAVIAN REINSURANCE COMPANY LTD. |
| BERMUDA |
SIRIUS INSURANCE HOLDING SWEDEN AB |
| SWEDEN |
SIRIUS INTERNATIONAL INSURANCE CORPORATION |
| SWEDEN |
THE NORTHERN ASSURANCE COMPANY OF AMERICA |
| MASSACHUSETTS, USA |
WHITE MOUNTAINS ADVISORS LLC |
| DELAWARE, USA |
WHITE MOUNTAINS HOLDING (NL)B.V. |
| NETHERLANDS |
WHITE MOUNTAINS HOLDINGS (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WHITE MOUNTAINS INC. |
| DELAWARE, USA |
WHITE MOUNTAINS INTERNATIONAL S.A.R.L. |
| LUXEMBOURG |
WHITE MOUNTAINS INVESTMENTS BERMUDA LTD. |
| BERMUDA |
WHITE MOUNTAINS LIFE REINSURANCE (BERMUDA) LTD. |
| BERMUDA |
WHITE MOUNTAINS RE BERMUDA LTD. |
| BERMUDA |
WHITE MOUNTAINS RE FINANCIAL SERVICES LTD. |
| BERMUDA |
WHITE MOUNTAINS RE (GIBRALTAR) LIMITED |
| GIBRALTAR |
WHITE MOUNTAINS RE GROUP, LTD. |
| BERMUDA |
WHITE MOUNTAINS RE HOLDINGS, INC. |
| DELAWARE, USA |
WHITE MOUNTAINS RE HOLDINGS, LTD. |
| BERMUDA |
WHITE MOUNTAINS RE, LTD. |
| BERMUDA |
WHITE MOUNTAINS RE UNDERWRITING SERVICES LTD. |
| BERMUDA |
WHITE ROCK HOLDINGS (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WHITE SANDS HOLDINGS (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM ALAMEDA (GIBRALTAR) LIMITED |
| GIBRALTAR |
WM BECH (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM BELVAUX (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM CALETA (GIBRALTAR) LIMITED |
| GIBRALTAR |
WM CLAY (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM CUMBERLAND (GIBRALTAR) LIMITED |
| GIBRALTAR |
WM FINDEL (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM KAOLIN (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM KEHLEN (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM LAGUNA (GIBRALTAR) LIMITED |
| GIBRALTAR |
WM LIMESTONE (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM LINGER (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM MERL (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM MONTAGU (GIBRALTAR) LIMITED |
| GIBRALTAR |
WM OLM (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM QUEENSWAY (GIBRALTAR) LIMITED |
| GIBRALTAR |
WM REULER (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
WM VIANDEN (LUXEMBOURG) S.A.R.L. |
| LUXEMBOURG |
Certain other subsidiaries of the Company have been omitted since, in the aggregate, they would not constitute a significant subsidiary.