Microsoft's Gates to Leave ICOS Board

Mon Jan 10, 4:46 PM ET Business - AP

WASHINGTON - Microsoft Corp. Chairman Bill Gates (news - web sites) will resign from the board of drug developer ICOS Corp. to focus his attention on his board seat at Warren Buffett (news - web sites)'s Berkshire Hathaway Inc., according to a regulatory filing Monday.

Gates said he would resign from ICOS effective Feb. 9. The Bothell, Wash., company codeveloped erectile dysfunction treatment Cialis.

In a letter sent to ICOS Chairman Paul Clark last Tuesday, Gates explained his resignation.

"Just prior to Christmas, Warren Buffett asked me to join the board of directors at Berkshire Hathaway. I agreed, and this was announced just a few days later. I hadn't expected this, but given my friendship with Warren and my interest in helping out in any way he ever asks, Berkshire is now my highest priority for board membership," Gates said in the letter.

"A challenge for me has always been managing my time effectively so that I feel confident about my contributions at Microsoft, my foundation and at home. With this in mind, I have always limited my involvement to only one outside public board," Gates said.

He further said that "joining the ICOS team in 1990 was a great opportunity for me because of my interest in science and the biotechnology business. It's been immensely interesting to have been involved with the company from its early days ... I plan to be a long-term shareholder in the company."

Berkshire Hathaway elected Gates as a director to fill a vacancy created by the death of Buffett's wife, Susan T. Buffett.

ICOS shares closed Monday at $26.85, down 2 cents, on the Nasdaq Stock Market.