The House Foreign Relations Committee has voted to expel private insurance companies from most operations of the Overseas Private Investment Corp., the quasi-official risk insurance agency that protects U.S. business against expropriation by foreign governments.

The Committee's action stops short of a companion move in the Senate to dissolve OPIC altogether, but it reflects mounting fears in Congress that the investment insurance program has become dominated by U.S. multinational corporations who operate in a handful of industrialized and economically secure nations.

Senate steps to dissolve OPIC are based largely on the promise that the program has become an expensive, government-backed subsidy of a few big corporations and that it has outlived its usefulness.

The House proposal to eliminate private insurors' involvement in OPIC would reverse a 1974 mandate by Congress that the indemnification program be taken over gradually by the private sector, with a 1980 deadline for that goal.

About two dozen insurance companies have been involved as subcontractors, in effect, in underwriting overseas investment insurance policies. The companies operate as a consortia, called the Overseas Investment Insurance Group.

Under the House proposal, the group would be broken up except for a re-insuring collective, and the business would be absorbed by OPIC The expanded OPIC would underwrite all investment insurance, backed by the U.S. Treasury.

Although OPIC ostensibly was set up to encourage private investment in lesser-developed countries - as well as to stimulate foreign investment by small business - the reverse has occurred, according to testimony in recent congressional hearings.

Three big multinationals last year received 29 per cent of the insurance issued by OPIC, and nearly two-thirds of the dollar volume of OPIC insurance has become concentrated in just seven countries - Brazil, the Philippines, South Korea, Indonesia, Taiwan, the Dominican Republic and Yugoslavia.

Sen. Frank Church (D-Idaho), the most vocal critic of OPIC has complained that U.S. multinationals have monopolized the $6.2 billion of OPIC program.

OPIC insures foreign investments against loss by expropriation, inconvertibility of currency, and by war, revolution and insurrection. It backs, the indemnity with the full faith and credit of the U.S. Treasury.

In doing so, it provides U.S. businesses with insurance at a fraction the normal cost.

Rep. John J. Cavanaugh (D-Neb.), author of the amendment to strike private insurance companies from OPIC, said in an interview yesterday, "The source of OPIC's problems are the private insurance companies." The amendment was attached to the annual bill to coninue OPIC.

He said the companies collected $5.3 million in premiums in the last three years, while paying out only $225,000. Pending claims total $1.8 million.

Total liability exposure for the firms is $2 million, against proceeds of $5 million, Cavanaugh said. He called it "a huge ripoff of the clients and OPIC," and complained it reflected the insurance companies' conservatism and unwillingness to indemnify risk for small investors operating in margainly stable nations.

"The dominance of OPIC by big multinationals is a direct result of the privatization of the program.I see no reason why OPIC can't continue on a cash basis, even at reduced premiums," he said.

Under his plan, OPIC would over its own policies with revenues from premiums, without government subsidy. Private insurance firms could continue to operate as re-insurors.

Cavanaugh said he presented his compromise plan to Church, but the Idaho senator indicated he wanted OPIC disbanded altogether because it has become a low-cost service to big corporations.