Continental Airlines, which had proposed to drop a popular promotional program in which grocers and retailers offered customers low-cost travel certificates on the airline, yesterday backed off temporarily after protests from Giant Food and other companies taking part in the promotion.

"The bottom line is, consumers spoke up and we listened," said Ned Walker, a spokesman for Continental.

In the Washington area, Giant offered the promotion, which attracted more than 100 banks, grocery stores and other retailers nationwide. Giant offered customers with $89.95 worth of grocery receipt tapes a chance to buy a travel certificate for $89.95 good for one-way travel anywhere Continental flies domestically from any of the three Washington-area airports.

That represents more than 100 destinations, said Terry Gans, vice president of advertising for Giant.

Gans said that tens of thousands of customers had taken advantage of the promotion, which Giant had advertised.

"It was a very, very successful promotion," said Bruce Hicks of Continental. As the cost of jet fuel increased and fares went up, "what was a really good deal became a spectacular deal and demand began to skyrocket," he said.

Last week Continental told Giant and other retailers it was stopping the promotion at once. But Giant and others who had contracts to offer the promotion for longer complained.

"Upon receipt of the letter we contacted Continental right away and reached agreement that we could continue making these available through Aug. 31," as the grocery chain had advertised it would, said Gans. Gans said Giant was concerned about customers who have been saving receipts but had not accumulated enough to qualify.

Retailers who have been using the promotion have agreed not to advertise it further. Walker said Continental wants to slow down demand for the program, which has been stunningly successful, but that "anyone participating or who planned to participate will not be disappointed.

The travel certificates entitle users to travel Q-class , a nonrefundable fare that requires a seven-day advance reservation. Those seats are available in limited quantities on each Continental flight.

"What we have been saying all along is to check other fares to make sure this is the cheapest and call to make sure you can get a reservation before buying the certificate," said Gans