A bipartisan panel of senior foreign policy experts has urged the Reagan administration to maintain many aspects of the Carter administration's policies toward the Soviet Union, while recommending a few significant departures.

The panel, chaired by former governor William Scranton of Pennsylvania and sponsored by the United Nations Association, includes academic experts and officials from recent Democratic and Republican administrations.

Its recommendations are to be presented to Secretary of State Alexander M. Haig Jr., Secretary of Defense Caspar W. Weinberger and national security affairs adviser Richard V. Allen Monday.

The panel recommended that Reagan maintain the Carter administration's partial embargo on grain sales to the Soviets, although President Reagan campaigned against the embargo. It also urged the new administration to respect the limits in the SALT II treaty while trying to reach a new pact.

The panel proposed that Reagan continue some form of human rights policy, and:

Recommended increasing the readiness of U.S. conventional armed forces, which it said is currently "the single most important and pervasive weakness of the U.S. national defense posture."

Split on the MX missile, with a majority saying the United States should seek alternatives and a minority saying the administration should proceed with plans for deployment of the missile system in Utah and Nevada.

The panel noted that the years-long tendency of Washington officials to deal directly with Soviet Ambassador Anatoliy F. Dobrynin on important policy issues, rather than going through the U.S. ambassador in Moscow, "has greatly undermined the stature and morale of U.S. officials in Moscow."

In addition to Scranton, the panel included retired Lt. Gen. Brent Scowcroft, national security affairs adviser during the Ford administration; Helmut Sonnenfeldt, who served as a top aide to former secretary of state Henry A. Kissinger; Charles W. Yost, former U.N. ambassador; Stanley Resor, former undersecretary of defense; Marshall I. Goldman of Harvard's Russian Research Center, and Seweryn Bialer, director of the Research Institute on International Change at Columbia University.