The Reagan administration today dismissed as insufficient Soviet leader Mikhail Gorbachev's announcement of a freeze on deployment of intermediate-range missiles, saying it would leave the Soviets with a 10-to-1 advantage.

Presidential spokesman Larry Speakes said "at first blush" the moratorium "seems to revive prior Soviet efforts designed to freeze in place a considerable Soviet advantage."

National security affairs adviser Robert C. McFarlane said President Reagan was "disappointed" in Gorbachev's initiative because it appeared to reiterate a concept that the late Soviet leader Leonid Brezhnev had proposed in June 1982.

Administration sources said Gorbachev's statement was particularly disappointing because it indicated a lack of sincerity about the recently resumed Geneva arms negotiations. The officials expressed irritation at Gorbachev's public disclosure of the freeze at a time when negotiations are going on.

Speakes said the United States would continue the deployment of Pershing II and cruise missiles in Western Europe, requested by NATO in the 1979 "dual-track" decision to counter the Soviet missile buildup while pursuing negotiations.

White House officials said Gorbachev's remark on desiring a summit meeting with Reagan was similar to his earlier acceptance of the "idea" of a summit. Reagan disclosed last week that Gorbachev had responded to his invitation for a summit.

No time or place has been set for a summit, Speakes said. "I don't see any link" between the summit and the Soviet missile moratorium, he said. Other officials have said that discussions on an agenda could take place May 14 when Secretary of State George P. Shultz and Soviet Foreign Minister Andrei A. Gromyko are scheduled to meet in Vienna. A fall summit, possibly at the United Nations in September or October, is the most likely option, officials said.

It was learned that Gorbachev's order for a moratorium on missile deployment had been disclosed several weeks ago to U.S. negotiators at the Geneva arms talks. The administration had been expecting Gorbachev to make public the moratorium for at least 10 days.

A U.S. official summed up the response by saying, "Nothing new."

Speakes said the Soviets had been adding new SS20 missiles at a "rapid clip" and hold a 10-to-1 edge over the West in intermediate-range missile deployments in Europe. Intermediate-range missiles are one of the three topics under discussion in Geneva. The others are long-range (strategic) weapons and space weapons.

The Soviet Union broke off earlier negotiations on intermediate-range missiles after 1983 deployment of the Pershing II and cruise missiles in Western Europe.

At the time, the United States had proposed that each side reduce missile arsenals to roughly equal levels. Reagan had originally proposed a "zero-zero" option to eliminate intermediate-range missiles in Europe.

"If they want a freeze, fine," Speakes said. "But that's not enough. The next step is to move to reductions, and they enjoy such a distinct advantage that it's incumbent upon them at Geneva to discuss arms reduction, not a freeze at an advantage to the Soviet Union."

Speakes said of the Gorbachev proposal, "As far as that being any exchange for ceasing U.S. deployment which is substantially smaller than the Soviet deployment, no."

The latest U.S. estimates are that the Soviets have deployed 414 SS20 missiles, each with three warheads. About two-thirds are aimed toward Europe, the rest toward Asia.

The United States has deployed an estimated 125 Pershing II and cruise missiles in Western Europe, with an eventual goal of 572. These missiles each have one warhead.

Reagan, vacationing at his ranch near here, was informed of Gorbachev's remarks in a telephone call this morning from McFarlane, who later went to the ranch to brief the president.

Speakes read to reporters a statement that he said reflected Reagan's views. The statement noted Soviet advantages in intermediate-range missiles, and added:

"We believe the more pressing need is to achieve significant reductions in U.S. and Soviet offensive missiles and this can be done in the talks at Geneva.

"Stability requires that a balance be established at the least possible level," Speakes said. "Stability cannot be achieved by maintaining a lopsided balance accompanied by refusal to reduce" nuclear missile arsenals, he added.

"The president believes that we can achieve reductions and looks to the Soviet Union to fulfill its pledges to the same end. He believes that talks in Geneva can accomplish this and calls on the Soviet Union to join in this effort."

He added, "Also worth noting is that previous Soviet statements of intent to establish a moratorium . . . have been followed by continued deployment."