Updated from 4:52 p.m. ESTPaul Pressler has fallen out of the Gap ( GPS). The San Francisco-based retailing giant, struggling amid a two-year-long sales slide, said Monday that its board and Pressler "mutually agreed" that he will step down as president and CEO. He also will resign his seat on the company's board. Robert Fisher, a 30-year Gap veteran and the company's current nonexecutive chairman, will serve as president and CEO on an interim basis. The company formed a board search committee to find a new CEO. The move ends a more than four-year reign by Pressler that has largely been marked with disappointments. While Pressler halted a sales slide when he first arrived, Gap has been in the midst of a seemingly interminable slump and has long promised a turnaround that has yet to come to fruition. "It had to happen," says Howard Davidowitz, chairman of Davidowitz & Associates, a New York-based retail consulting and investment banking firm. "He had lost all credibility with every constituency he dealt with -- the employees, the shareholders, the board, Wall Street, the suppliers. There was nowhere to go." Earlier this month, Gap said same-store sales for the key December period tumbled a steeper-than-expected 8%, and the company slashed its full-year earnings forecast. For all of 2006, Gap's same-store sales, or sales at stores open at least a year, dropped 7%. That was on top of a 5% decline in 2005.