Giant Food Inc., the Washington area's dominant supermarket chain, yesterday reported a 7.3 percent increase in its first-quarter earnings on a revenue gain of 6.2 percent.

The Landover-based company, which has a market share of nearly 47 percent in the region in the latest rankings by the trade publication Food World, said its profit totaled $28.5 million (48 cents a share) for the quarter ended May 19, compared with $26.5 million (44 cents) in the same period a year ago. Revenue rose to $769.3 million for the quarter from $724.5 million in 1989.

Giant's profit as a percentage of revenue -- 3.70 percent in the first quarter, an improvement over the 3.66 percent in the same quarter a year ago -- compares with an industry average of about 1 percent.

The 150-store chain also said it was pleased with the results of its "Apples for the Students" program, under which it gave computers and other equipment and software to area schools in exchange for Giant cash register receipts.

Giant handed out 5,000 computers at a cost to the company of $3.5 million and said it is considering whether to resume the program in the fall.