NEW DELHI, MAY 6 -- India has launched a visible effort to gain influence in Afghanistan, publicly embracing President Najibullah at a critical point in the decade-long Afghan conflict.

With Soviet forces only a week away from the official beginning of their withdrawal from Afghanistan under accords signed in Geneva in April, the Indian campaign marks an attempt to help shape the future government in Kabul, whose composition could have a significant impact on the already tumultuous politics of the South Asian region.

Indian officials publicly welcomed Najibullah and other members of his government for a three-day visit that ended today and included at least three meetings or official dinners with Prime Minister Rajiv Gandhi.

Portraying Najibullah as trying to build a "pluralistic, multiparty" society in Afghanistan, an Indian official charged today that Pakistan, which hosts the seven-party Afghan rebel coalition and about 3 million refugees, is attempting to install a fundamentalist Islamic government in Kabul.

"They are trying to foist a government of their choosing on Kabul. Arms are being furnished to their favorites," especially to fundamentalist rebel leader Gulbuddin Heckmatyar, said an Indian official.

Indian officials familiar with the Afghan-Indian discussions said they expect new efforts soon by Najibullah to coax Afghan exile leaders, including ex-King Zahir Shah, to return to Kabul.

"The impression we get is that he will offer more of a role for the king," said one Indian official familiar with the talks.

At a press conference today, Najibullah again called for the return of the former king, who was deposed by a cousin in 1973, but he also implicitly rejected a suggestion that he might step down as president in an effort to forge national unity. "The recent grand council elected a president to serve for seven years," Najibullah said.

Some western analysts have predicted the fall of the Najibullah government after the estimated 115,000 Soviet troops in Afghanistan are withdrawn, and that a new violent struggle for power will follow.

The seven-party Afghan resistance coalition is composed of two wings united in their opposition to the present Soviet-supported regime. Four of the parties are identified with a more fundamentalist version of Islamic beliefs while the other three, while ardently Islamic, are more closely tied to Afghan traditionalism and are considered by analysts to be more moderate.

With a large Moslem population and the unresolved status of predominantly Moslem Kashmir, India is highly sensitive to any developments that could inflame religious passions. Analysts here often have expressed fears of the impact of a new fundamentalist Islamic force in the region.

In addition to Gandhi and President R. Venkataraman, Najibullah saw most major Cabinet members during his visit to the Indian capital.

The trip was one of the first official state visits that Najibullah has made outside of Soviet Bloc countries or major Soviet allies. He stopped in India two months ago on the way home from a visit to Hanoi but Indian officials stressed that it was an unofficial visit and distanced themselves from the Afghan leader.

Indian officials today reacted sharply to suggestions that their embrace of Najibullah may have been motivated by India's close ties with Moscow.

"The belief we are interested only in pro-Soviet interests is nonsense. We are not acting as anybody's surrogate," said a well-placed Indian official.

"We have well-founded worries about the impact of fundamentalism on our own security."

While openly buttressing the Najibullah government at this stage, the Indian policy appears to be aimed at blocking what New Delhi sees as Pakistan's efforts to gain dominating influence in Afghanistan through a government that also would be fundamentalist in character.

Although the visit in New Delhi gave Najibullah a much-needed public boost, talks on assistance appear to have yielded only modest results. Indian officials said New Delhi would expand a hospital and an industrial park in Kabul built with Indian aid but promised little more immediately.