BOSTON -- One of the world's richest universities, feeling the effects of the global economic recession, said Tuesday it will lay off about 275 workers in the next month and cut hours for 40 more.

The cuts will mainly affect administrative and professional positions, according to e-mails sent by the university's vice president of human resources, Marilyn Hausammann, and Harvard President Drew Faust. The other half of the cuts will be among clerical and technical staffers.

"With compensation accounting for so high a proportion of our budget, we will enter the 2009-10 academic year with salaries held flat for faculty and exempt staff; we have also offered a voluntary early retirement program in which more than 500 staff members across Harvard have chosen to participate," the Faust e-mail read.

More efforts will be made to cut expenses beyond the layoffs, the e-mail said.

"We regret the impact this will have on the lives of our valued colleagues. This decision was driven by the financial challenges facing the university after a projected 30 percent drop in our endowment, as well as pressure on other revenue sources," Hausammann's e-mail said.

University managers have been asked for the last six months to "scrub" budgets for "non-personnel" savings, the e-mail said, and development in Allson was slowed as well, but it wasn't enough to prevent the need for layoffs.

University spokesman Kevin Galvin said it was difficult to determine the mood around campus following the announcement, although he indicated the cuts were probably not unexpected because "everyone has known at some point there would be some changes."