The travel agency which made reservations for 11,000 American sports fans to attend the Moscow Olympics now wants to get in line with the corn farmers, grain exporters and chicken packers who've been bailed out by the federal government.

The agency, RTB-Olympic Travel Ltd., already has paid the Soviets $7 million and is worried about getting the money back if the United States pulls out of the games.

Several hundred customers already have called about canceling their trips, according to Ronald Dietrich, a Washington attorney who represents RTB-Olympic.

Dietrich said yesterday a federal judge in New York has ordered the travel agency not to give refunds until it is determined whether the Russians will return the money they've collected.

If the Russians won't, all 11,000 Olympic fans may have to share the loss, the judge ruled.

"We would hope for some legislative effort to indemnify the people who made reservations," Dietrich said.

"Why should Mr. and Mrs. America, who put up their hard-earned money to go to the Olympics, have to pay because the federal government decided to pull out?" he asked.

The government already has pledged to pay as much as $3 billion to others who will lose money as a result of President Carter's decision to retailiate for the Soviet Union's invasion of Afghanistan.

The government has agreed to buy the 17 million tons of American grain the Soviets were going to buy until President Carter canceled the sales Jan. 4. That will protect farmers and grain exporters from losses expected to run into the billions.

The Department of Agriculture has agreed to buy several million chickens that were bound for the Soviet Union until Carter canceled their trip. The chickens already were packaged with Russian labels, making them difficult to sell in American supermarkets.

The Department of Commerce has talked about giving government aid to other companies that have lost business because the government cut off exports to the Soviet Union.

What happens to the Olympic-bound tourists won't be determined until after a decision is made on whether to send a U.S. team. The U.S. Olympic Committee is meeting this weekend in Colorado to discuss that.

Dietrich said RTB-Olympic Travel went into court in New York on Thursday to try to head off a rash of lawsuits demanding refunds from fans who've already decided not to go to Moscow. The judge set up the framework for a class-action lawsuit that will assure all the travelers are treated equitably.

RTB-Olympic has an exclusive contract with the U.S Olympic Committee and the Soviet government to arrange tour packages to the games for Americans.

About 11,000 tours have been booked, most of them two-week packages costing $1,550 per person and some three-week tours going for $1,850, Wallace Lawrence, president of RTB-Olympics, said.

The Soviets insisted on selling only package deals, which included transportation, hotels and food, so they could keep close control over the unusual influx of American tourists.

Lawrence said his company, working through more than a thousand travel agencies across the nation, has collected about $15 million in advance payments from Olympic fans and already has paid nearly half of it to the Soviets.

The contract with the Soviets provides for refunds, he said, but it is "a crystal ball question" as to whether the Americans will be able to get their money back. "The fact that we're dealing with a country, not with individual companies, gives us confidence that the country will stand behind all agreements," he said.

If the Russians refuse, RTB cannot make up the loss and has no insurance to cover that contingency, Lawrence said. "We explored the possibilities with Lloyd's (of London) and everybody else," he said. "We could not get what we could call 'political insurance'."

The NBC television network, which paid the Soviet government about $85 million for rights and facilities to broadcast the Olympics, was able to buy insurance from Lloyd's. For a $2 million premium, NBC insured 90 percent of its costs, but still could lose up to $25 million in uninsured costs and other expenses.

Other businesses that had license to make an estimated $100 million worth of merchandise tied in to the summer games also stand to lose large amounts of money if the Olympics are canceled or the U.S. pulls out.