might have been shopping for a bounce in its stock Tuesday when the California-based supermarket chain preannounced robust first-quarter revenue. Well, it worked in the premarket.

For the quarter ended March 26, revenue increased approximately 12% to $8.6 billion. Sales in the year-ago quarter were impacted by a grocers' union strike in southern California that covered an eight-week reporting period. Excluding sales at strike-affected stores, same-store sales increased 4.4%, thanks partly to the earlier Easter holiday.

The consensus forecast is for revenue of $7.91 billion and earnings per share of 24 cents, according to Thomson First Call.

The company cited its improved product offering, saying it had "dramatically increased the quality of perishables, introduced a growing stable of proprietary products, significantly increased our offerings in prepared meals, developed a store concept called the Lifestyle store and improved our industry-leading customer service."

Safeway reports formal earnings May 3.

In the premarket, the stock was at $20.32, up $1.67, or almost 9%.