Attorney General Stephen H. Sachs announced that Unity Mortgage Corporation, a subsidiary of a large Illinois-based financial institution with outlets in Maryland, has become the fourth mortgage banking firm to reach an agreement with his office on charges it refused to honor mortgage commitments.

Unity Mortgage, a subsidiary of Unity Savings Association of Chicago, which has a Washington division with branches in Kensington, Columbia and Annandale, has agreed to reimburse consumers for any losses they sustained because of the company's actions, Sachs said.

Consumers have complained that the lending institutions made commitments to them about the interest rate or number of points they would have to pay for mortgages.

The attorney general and the bank commissioner alleged that Unity Mortgage issued both oral and written commitments to customers last summer, promising that the interest rates charged for FHA and VA loans would not go up if the market rate rose, and the rates on conventional loans would remain constant for 90 days after the original application.

However, when interest rates began to rise in late August, Unity Mortgage allegedly refused to honor its alleged commitments in violation of the State Consumer Protection Act, Sachs said.

Unity Mortgage Corporation specifically denies any wrong-doing, but said it would conduct an internal audit to determine which homebuyers or sellers are entitled to a refund.