HCC CLOSES ITS ACQUISITION OF ILLIUM WITH
ADDITIONAL SYNDICATE CAPACITY FROM MUNICH RE

HOUSTON (December 22, 2005) . . .
HCC Insurance Holdings, Inc. (NYSE symbol: HCC) announced today that the Company had closed its recently announced acquisition of the remaining 80% of the outstanding shares in UK based holding company Illium Insurance Group Ltd., for an undisclosed consideration.

Illium is the owner of a Lloyd’s Managing Agency that manages syndicate 4040 at Lloyd’s and which specializes in UK third party liability, employers’ liability and commercial motor. For more information, please visit their website at www.illiuminsurance.com.

Also, Illium has entered into an agreement with Great Lakes Reinsurance (UK) Plc (“GLUK”), part of the Munich Re Group, whereby GLUK will co-insure risks underwritten by Illium with effect from January 1, 2006. Under this arrangement, GLUK will provide approximately £30 million of premium capacity part of Illium’s total of £85 million for 2006.

Stephen L. Way, Chairman and Chief Executive Officer of HCC, said, “This completes our entry into the Lloyd’s market and we are extremely pleased to have reached an agreement with the Munich Re Group for the 2006 underwriting year.”

HCC is an international insurance holding company and a leading specialty insurance group since 1974, based in Houston, Texas with offices across the USA and in Bermuda, England and Spain. HCC has assets exceeding $6.6 billion and is rated AA (Very Strong) by Standard & Poor’s and A+ (Superior) by A. M. Best Company.

For more information, visit our website at www.hcch.com.

©2005 HCC Insurance Holdings, Inc.