FIRST AMERICAN <FIAMA> SEES GAIN FROM SALE First American Bank and Trust Co said its 88 pct owned Associated Mortgage Investors <AMIMS> subsidiary has sold its New England operations for about 2,100,000 dlrs in cash and 1,300,000 dlrs in stock, resulting in a first quarter gain for First American of about 1,200,000 dlrs after tax. The company said the sale will complete Associated's withdrawal from the general contracting business.