MOSCOW, OCT. 16 -- The Soviet Union has engaged American industrialist Armand Hammer in its bid for a political solution to the war in Afghanstan, but western envoys here said the shuttle diplomacy is unlikely to yield early results.

Hammer, who met this week with party leaders in Kabul and Moscow, said in a news conference here yesterday that Soviet Foreign Minister Eduard Shevardnadze had personally dispatched him on a peace mission to Afghanistan.

Hammer, 89, said he expects to fly to Pakistan, Italy and the United States in the next few days to meet with key figures involved in the search for a solution to the battle between the Soviet-backed communist regime and Moslem rebels.

The assignment for Hammer, the head of California-based Occidental Petroleum, comes a week before U.S.-Soviet talks on the Afghan war are due to take place here. When Secretary of State George P. Shultz arrives for talks Oct. 22-23, the war will be one of the principal items on the agenda, a U.S. official said.

The mission also comes on the eve of the eighth anniversary of the war and amid signs of morale problems affecting all of the warring factions, including 115,000 Soviet troops.

Afghan leader Najibullah already has agreed to give Afghanistan's former king, Mohammed Zahir Shah, and his son-in-law positions in a new ruling Cabinet, Hammer told journalists in Moscow. Hammer and Najibullah met in Kabul on Monday.

Western diplomats said Hammer's mission seems to be more an attempt at high-rolling shuttle diplomacy than a realistic effort to seek a solution to the war.

The diplomats said Hammer's bid is unlikely to result in an early withdrawal of Soviet troops, widely regarded in the West as the main obstacle to a political solution to the war.

The diplomats also expressed doubts that the kind of coalition government Hammer referred to could win a wide base of support. The majority of the members in a coalition of exiled Afghan rebels already have rejected proposals to include the former monarch in such an arrangement, they said.

One U.S. official said that Hammer is unlikely to resolve the political conflict because the main problem -- finding an acceptable peace-time government -- is wholly out of Washington's and Moscow's hands.

But during appearances before the media this week in Moscow and Tel Aviv, Hammer was upbeat about his chances.

He said that when he met yesterday with Shevardnadze, the foreign minister told him that party leader Mikhail Gorbachev had indicated that Soviet troops would be withdrawn from Afghanistan within a year.

"I think Mr. Gorbachev will give his word, set a date and keep his word," Hammer said. "He's very pragmatic. He's very decisive."

Hammer is scheduled to fly to Pakistan Sunday for talks with President Mohammed Zia ul-Haq, who maintains close links with rebel Afghan factions and representatives of 3 million Afghan refugees living in Pakistan.

Next week, Hammer plans a trip to Rome for possible meetings with former king Zahir Shah, ousted in 1973, and his son-in-law.

Najibullah told Hammer that the son-in-law would be accepted as prime minister.