Half of the 156 Safeway supermarkets in the Washington area have abandoned the practice of marking the price on each item. Instead, the stores post prices on the shelves where the merchandise is displayed.

The chain plans to eliminate item pricing at the remaining stores as soon as electronic checkout equipment can be installed, according to Safeway representative Ernest Moore. The changeover, however, could take months or even years to complete, he said.

Safeway is the second major area chain to drop item pricing. Giant Foods Inc. stopped marking individual prices on merchandise at its 126 stores six months ago at the beginning of a widely advertised program promising to pass on savings to customers in the form of lower "warehouse" prices. Now Giant has begun raising prices because of losses.

Giant was able to eliminate item-pricing at all of its stores because they are equipped with scanners that can ring up the price automatically by "reading" the code on the product.

Only 20 area Safeway stores have scanners. Another 60 Safeway supermarkets have electronic registers that can be programmed to ring up prices on about 300 items. An average supermarket has about 10,000 items.

About 60 cents of every grocery dollar spent here is rung up by Safeway and Giant stores.