Several large corporations, including Chrysler Corp., would take over responsibility for medical care of many of their retired workers on Medicare in an experiment nearing approval by the federal government.

Through the unprecedented program, the companies would receive a fixed monthly cash payment from the government. In return, they would take over responsibility for providing their retirees the doctor and hospital benefits of Medicare, the federal insurance program for 31 million elderly persons.

Reagan administration health officials said this week they hope that the plan will help to cap rising Medicare costs, as well as foster increased competition and consumer choice.

The companies themselves say they can save overall costs by adopting cost-cutting techniques, such as shuffling employers into health maintenance organizations or by more closely monitoring the health care. However, they would risk substantial losses if the government's payment did not cover the costs of covering the care.

"Chrysler has a more efficient health care system {than the government}," said former secretary of Health, Education and Welfare Joseph Califano, who sits on the auto manufacturer's board and has helped direct cost containment programs there. If the government proceeds with the new program, he said, "We're talking about potential savings of billions of dollars."

While retirees would not be required to leave the traditional Medicare plan, administration supporters of the experiment say these beneficiaries could gain broader health coverage by participating in the program.

Federal and corporate health officials disclosed progress of their talks at a two-day Department of Health and Human Services conference that concluded yesterday on the problem of rising retiree health care costs. They said a number of demonstration projects could be up and running as soon as 1988.

Officials said the company closest to an actual proposal is Chrysler, which is working with the United Auto Workers on the matter. Several other groups are also in serious negotiations with the government, including Deere & Co., the Amalgamated Life Insurance Co. and the Central States Health Welfare and Pension Fund, a big insurance plan for more than 100,000 Teamsters workers.

The conference provided the first public sign that a long-cherished, but controversial administration idea has moved from the drawing board to negotiations over specific proposals. If the experimental program goes into effect, it would be another step in the government's effort to make greater use of private companies in running Medicare. The government already contracts with more than 150 health maintenance organizations and other private health plans.

Medicare, which provides benefits for 31 million people, does not cover all of the health care costs of the elderly, charging various deductibles and copayments while excluding certain items such as prescription drugs.

Many companies pay for the non-Medicare health services received by their retirees, but the cost of this supplemental coverage has soared in recent years as health costs have risen and the population has aged.

The present Secretary of Health and Human Services, Otis R. Bowen, told the conference that by combining the Medicare benefit package and the supplemental package into a unified administration, companies will gain greater leverage to negotiate discounted prices with doctors and hospitals. Retirees would also be spared the necessity of filling out multiple claims forms, while they would not have to switch health plans when they retire, he said.

Bowen said the program provides a "real economic incentive for a company's health care manager to insist upon a prevention-based care concept."

The administration's plans, however, were challenged by Rep. Fortney A. (Pete) Stark (D-Calif.), chairman of an influential House subcommittee on health, who along with other legislators has raised concerns that Bowen and his aides are moving too quickly with their effort to tap the private sector in Medicare. Stark said that the administration's proposed experiment was tantamount to subsidizing corporate America's own retirement health cost problem.

The proposed experiment has "nothing to do with Medicare savings," Stark said. "It is a bailout for those corporations who have not seen fit to have good financial management." Stark recently introduced legislation prohibiting the administration from going ahead with any project larger than $10 million without congressional approval.

Despite Stark's criticisms, administration officials said they are proceeding with their negotiations on the experiment. Kevin Moley, one of the top Medicare officials working on the project, said that the government will soon turn over to Chrysler and other companies confidential Medicare data showing the amount of hospital and doctor care used by their retirees.

Chrysler's employe-benefits director, Walter Maher, said in an interview that the data will be important in showing Chrysler whether it can contain costs within the government's proposed payment rate -- which would amount to 95 percent of normal projected Medicare costs for their retirees. No final decision on whether to proceed would be made until this data is analyzed and until the company consults with the United Auto Workers, Maher said.