The Soviet Union like the United States has a powerful strategic nuclear weapons establishment, and it may have been important in the last-minute hitches thrown into the strategic arms limitation treaty (SALT) negotiations at Geneva last month.

According to informed administration sources, Soviet Foreign Minister Andrei Gromyko sought to modify language in the SALT II agreement that is supposed to limit the United States and Soviet Union to testing and depolying only one new type of land-based intercontinental ballistic missile (ICBM) during the five-year treaty period.

The Soviets, according to intelligence sources, already have four new ICBMs ready for testing. They are the products of the Soviet Union's three missile design bureaus -- a military-industrial complex that for years has been grinding out new ICBM models like Ford and General Motors put out cars.

If the new limitation standars as the United States wants it, the Soviet bureaucracy involved in missile production might face a cutback or at least a redirection. In addition, the powerful Soviet Strategic Rocket Forces, that nation's premier military service, might see a diminution in its growth.

Thus, according to U.S. analysts, Gromyko has made a last-minute effort to put a loophone in the new type of missile language that would permit the Soviet missile production complex and military arm to keep their current size and direction.

So far, U.S. negotiators have been firm in rejecting the Gromyko proposal and, according to one government source, "the Carter administration shows no sign of changing."

The draft SALT provision to limit new ICBM types is termed the only "radical step forward" in the new agreement, according to one arms control expert close to the negotiations.

It would prevent the Soviets from adding more warheads to any of their deployed missiles and would limit to 10 the number of warheads the one new type of missile could carry.

The provision was also described recently by one administration source as giving "a modest advantage" to the United States since limiting the Soviets to only one new type of missile may require them to change the operation of their three missile design bureaus.

In his final Geneva presentation on Dec. 23, Gromyko asked for a change in the definition of a "new type" of ICBM.

The American language said a "new type" of missile would be one that was more than 5 percent larger or 5 percent smaller than a current ICBM in specific areas such as external size and throw-weight -- the amount of payload it can carry into the atmosphere.

Gromyko accepted the 5 percent larger language, but suggested a missile design that was 20 percent smaller should not constitute a "new type."

"We're pretty sure at least one of their new models must fit into that definition," one source said.

The Soviet strategic establishment has come into power over the last 20 years.

Its major component is the Strategic Rocket Forces, which exercises control over all land-based ballistic missiles with ranges over 1,000 kilometers, or 620 miles. The rocket forces was created in 1959 and made a separate service within the Soviet military a year later.

In 1965, a ministry of general machine building was created as the military-industrial complex of the missile business.

Intelligence sources trace the development of Soviet ICBMs through four distinct missile design bureaus. Each bureau, sources say, has its own development, testing and production facilities.

Unlike sporadic U.S. missile building efforts, which are undertaken by a collection of corporations put together for a specific weapon, the Soviet missile bureaus automatically start work on a new ICBM once they have finished producing the old one.

Thus, sources point out, the bureau that produced the first big Soviet ICBM, the SS7 deployed in 1961, went on to build the enormous SS9 in 1965 and the SS18 in 1975.

A second bureau turned out the SS11 in 1966, a smaller missile compared by some to the U.S. Minuteman, though not nearly as accurate. This same bureau is now turning out successors to the SS11 in the SS17 and SS19. Deployment on those two has been under way since 1975.

A third missile bureau appeared in the 1960s specializing in solid-fueled missiles. Its SS13 was first deployed in 1968 and that was followed in 1970 by testing of the SS16, the first Soviet mobile ICBM.

The mobile SS16 has never been deployed. The SALT I agreement barred mobile ICBMs but analysts who have followed Soviet missile testing say the unreliability of the SS16 had as much to do with its never getting out of the test phase.

A two-stage mobile version of the SS16, called the SS20, was introduced in 1977 and has begun to be deployed in western Russia. With its 3,500-mile range, and three warheads per missile, the SS20 has become a matter of concern among European nations against whom it is targeted.

The fourth missile design bureau no longer works on weapons. It produced the SS18 in the early 1960s and then moved into the space launch area, sources say.

It is fear of that type of bureaucratic change that may have pushed the Soviet missile establishment to have Gromyko seek alteration of the new type of missile provisions.

One article said some U.S. press reports that the Soviet Union had held up the talks presented "a delibeately distorted picture." The second account, written by commentator Sergei Vishnevsky said American foes of detente were holding up agreement on the treaty.

It was the first time since the December negotiations between Secretary of State Cyrus Vance and Soviet Foreign Minister Andrei Gromyko that the Kremlin pointed an accusing finger at Washington.

Vishnevsky said the meeting "brought about agreement regarding a number of major issues" and that "resolve was expressed to finalize the work to prepare the agreement."

U.S. officials present at the December talks said privately at one point that a tentative agreement had been reached. When negotiations resumed the next day new Soviet demands prevented final agreement.