A five-year-old sex discrimination suit against Anne Arundel Community College that was nearing an out-of-court settlement recently now may have to go to trial instead because the school's insurer refuses to pay off the $550,000 to $700,000 claim, college officials said today.

The class action was brought by 89 female faculty members, who charged that the school discriminates against them in pay, benefits and promotions. About half of the school's 175 full-time faculty are women.

The officials contended today that they have been "abandoned" by the insurance company and warned that being forced to engage in expensive litigation could have financial repercussions on salaries and tuition at the 9,000-student institution. Anne Arundel County, also named in the suit, notified the college today that it would not pay the settlement costs and that the money would have to come out of the college's operating budget.

Board President Irene Newhouse said the board had been close to coming to terms for a settlement and had been anxious to avoid going to court to cut down on further legal expenses, which are estimated to total $78,000 thus far.

Newhouse warned that if the college has to pay a settlement out of this year's budget, it would "create a severe financial hardship for the college," and might mean pay reductions for all employes or an increase in tution." The college's operating budget this year is $16 million.

However, Rignal W. Baldwin Jr., an attorney for the women, charged today that the board was "maneuvering and posturing" and suggested that the college had dragged its heels on a settlement. Women involved in the case declined to comment.

The school has appealed to Maryland insurance officials and is awaiting a decision today from assistant state insurance commissioner Thomas Raimondi on whether CNA Insurance Co. of Chicago should pay any back pay damages that are part of a settlement with the women. Lawyers for the insurance company said in a hearing before Raimondi earlier this week that the college was not entitled to coverage under its indemnity policy against civil rights claims because the company believed it had discriminated against the women.