The Reagan administration has sent to Congress sweeping proposals that would end the right to sue for triple damages in most civil antitrust cases.

In an attempt to give American high technology a boost in world markets, the administration plan would allow competing companies to run joint research and development projects without fear of the most stringent antitrust penalties.

The package was approved by the Reagan Cabinet last week; parts of it have been leaked in speeches and interviews by Assistant Attorney General William F. Baxter, head of the Justice Department's antitrust division.

The proposals are expected to meet strong opposition on the Hill from those who see it as evidence of the Reagan administration backing off strict antitrust enforcement. Both Rep. Peter Rodino (D-N.J.) and Sen. Strom Thurmond (R-S.C.), chairmen of the House and Senate judiciary committees, have indicated they might consider holding hearings.

Nonetheless, Hill sources said it is unlikely that either committee will move quickly on the administration proposals, which represent major changes in antitrust law.

According to antitrust specialists, a key element in the administration proposal concerns removing all research and development collaboration, considered "intellectual property," from the area that would bring triple damages.

That loosening of the antitrust law has been favored by the Department of Commerce and pushed by the electronics industry as a way to help American high-tech firms compete successfully with the Japanese and to encourage innovation. That part of the proposal is being sold on the Hill as a way to strengthen the sale of American exports.

Some critics, however, contend that the change is likely to benefit large companies who do little original research while leaving untouched the small enterprises that produce most of the innovative new technology.

The administration's new antitrust plan would remove a broad category of cases from liability for triple damages. Triple damages no longer could be sought for alleged price-fixing activity that could be legal, but that violates what is known as "the rule of reason" in civil cases. These cases often involve issues of vertical antitrust such as suits against manufacturers by stores claiming that sales agreements are depriving them from distributing popular products.

Under present law, winners of civil suits in such cases can get three times the amount of damages they suffered.

While only actual damages could be assessed in those cases, the new administration proposal would add interest payments from the date the case was filed. Some observers noted that, in long-running cases such as the 13-year International Business Machines Corp. case, the interest could bring the total award close to triple damages.

Baxter would retain triple damages only for cases considered "per se"--or intrinsic--violations of antitrust laws, such as price-fixing agreements between competitors or bid rigging.

A third part of the new administration antitrust proposal would allow inventors to gain a greater monopoly from their patents. It would make it harder for a patent holder to lose his monopoly because he misused the patent by placing conditions on its licensing. Baxter said the patent holder should lose his exclusive rights only if the conditions placed on the use of his property cause "competitive harm."

The Justice Department view is that the present law has not protected the rights of inventors properly.

To further achieve that aim, the administration has proposed extending a patent on a process to the product that comes from it. According to Justice Department sources, this would prevent manufacturers in foreign "patent havens" from making an unpatented product using a patented process and then shipping it to this country for sale.