CHICAGO -- Matthew V. Storin resigned yesterday as editor of the Chicago Sun-Times after less than 10 months in that position. Kenneth D. Towers, the newspaper's managing editor, was appointed executive editor and vice president, effective immediately.

Sun-Times staffers were told of the management changes in a memo from Publisher Robert E. Page and at a brief newsroom meeting at about 6 p.m.

According to several people who attended the meeting, Storin cited as a reason for his resignation philosophical differences with Page over how to increase the paper's circulation and make it more successful. "There are no great moral issues here," he said, referring to his decision to resign.

Storin told some of the staffers that he hadn't made any decision on another job. Efforts to reach Storin and Page were unsuccessful.

Storin, 44, came to the Sun-Times in September after a stint with U.S. News & World Report magazine and a long career at The Boston Globe. At the Sun-Times, he filled an editor's spot vacant since last July, when an investor group led by Page acquired the newspaper for $145 million from Rupert Murdoch's News Corp.

Rumors began circulating several months ago that Storin was unhappy working with Page. Sun-Times sources, who asked not to be identified, suggested that the two men differed in their styles and approaches to the paper and that their relationship had grown cooler in the last few weeks. The sources said they doubted there were significant disputes between the men over the tabloid's news coverage or headlines.

The sources suggested that Storin may have been chafing under financial restrictions imposed by top management, which has been concerned about a recent increase in interest rates and an anticipated increase in newsprint prices.

However, in a statement yesterday, Page said the Sun-Times soon will complete its fiscal year with record earnings.