AOL co-founder Steve Case Monday resigned from Time Warner's board of directors, another step in the symbolic dismantling of a merger that's regarded as one of the biggest debacles of the dot-com era.

Case said he is leaving Time Warner to devote greater attention to his new entrepreneurial venture, Revolution, an investment company Case launched in April with stakes in an assortment of healthcare and hospitality businesses. Case said he will remain a major Time Warner shareholder.

Case became chairman of Time Warner, based in New York, in January 2001, as the company closed its merger with AOL. He relinquished the position in May 2003, not long before the company dropped AOL from its name and reverted back to Time Warner.

In the years since, Time Warner has struggled to rekindle AOL's growth in a market filled with challengers, from DSL and cable-modem providers offering faster connections to content companies like Yahoo and Google that rival AOL for advertising sales. AOL had 20.8 million U.S. subscribers as of June 30, down nearly 3 million from its total a year earlier.

In a statement announcing his departure from Time Warner, Case said he believes AOL "can return to its past greatness." He praised "a renewed focus on AOL at Time Warner" over the past few months.

Time Warner is rumored to be in talks with companies including Google, Yahoo and Microsoft about selling part or all of AOL.

Time Warner Chairman and CEO Dick Parsons issued a statement thanking Case for his years of service to the company. "As Steve is one of our major individual shareholders, we'll look forward to his wise counsel as the company continues to move forward. He will be missed," Parsons said.

The IDG News Service is a Network World affiliate.