By John Rogers

Netscape Communications Corp co-founder Marc Andreessen will step down from his post as chief technology officer at America Online Inc and be replaced by former Sun Microsystems Inc executive William Raduchel. The move is seen by many as another sign of the growing relationship between AOL and Sun since the blockbuster deal in which AOL acquired Netscape last November and the three subsequently formed the Sun-Netscape Alliance.

Andreessen has been with AOL since its acquisition of Netscape closed in February and was the company’s first CTO. He will stay on in a part-time strategic advisor role, with a primary focus on emerging technologies and new investment opportunities for AOL. The company said he will split his time between working with start-ups and working with AOL on technology issues and potential investments.

If Andreessen’s initial appointment at AOL seemed like an ill fit for a man whose passion appears to lie in new opportunities, his desire to step aside comes as less than a shock. Marc wanted to spend more time working with start-ups, and we are pleased that this arrangement will allow him to do that in a manner that furthers our investment objectives, AOL chief executive Steve Case said in a statement. Obvious differences in corporate culture between Netscape and AOL may have also factored in Andreessen’s decision to take a lesser role.

Raduchel, meanwhile, comes to AOL having most recently held the position of chief strategy officer at Sun, where he was also a member of the company’s executive committee and helped broker the Sun-Netscape Alliance. At AOL, Raduchel will be responsible for the company’s technology strategy, focusing on its architecture and strategic alliances.

After joining Sun from Xerox Corp in 1988 as vice president of corporate development and planning, Raduchel served as chief information officer from 1990 to 1998, when he assumed his current position. Before that, he was chief financial officer from 1989 to 1991 and also VP of Human Resources from 1991 to 1992.