XL boss Brian O'Hara has resigned from the board of XL spin-off Security Capital Assurance.

His resignation, which took immediate effect, comes exactly a month after it was announced he is to retire as president and CEO of XL Capital next summer.

Mr. O'Hara (pictured right) has sat on the board of SCA since it made its initial public offering in August 2006.

Paul Giordano, SCA's chief executive officer, said: "On behalf of SCA, I thank Brian for his committed service and dedication to the company during his tenure.

"Brian's experience and leadership have been invaluable to SCA."

Regarding his departure, Mr. O'Hara said: "It has been my pleasure to serve on SCA's board of directors. I believe that the remaining members of the SCA board will provide excellent leadership for SCA."

XL is a 46 percent shareholder in SCA and has a right to appoint a replacement to Mr. O'Hara on the eight-strong board of directors.