University of Southern Maine officials announced today they expect to make more layoffs in the coming weeks, as they work to balance the budget.

Interim President Joseph Wood told University System trustees that USM had cut 91 positions so far to save $5 million. It saved another $1 million through reductions in equipment purchases.

But the university will have to make more staffing cuts to achieve the $7.5 million in savings needed to keep this year’s budget on track. The bulk of the staff cuts were made through attrition, while 18 staffers were laid off.

University spokesman Robert Caswell said an unspecified number of additional layoffs will be required to keep the budget on course. Originally, the financially-troubled university planned to trim back the budget by $2 million annually through 2010. But earlier this year Wood decided to step up the cuts to return the university to financial health sooner.