The joint annual meeting of the International Monetary Fund and World Bank ended yesterday with the rich nations pledging greater help to the poor and the poor nations dampening some of their past critical rhetoric.

Although the two Bretton Woods institutions are under increasing pressure to change, a consensus seemed to emerge that the IMF and Bank -- and the major countries that support them -- are making a genuine effort to help the emerging nations cover their growing deficits.

Both institutions propose to increase their lending on more generous terms. At a concluding press conference, IMF Managing Director Jacques de Larosiere went so far as to say that any "stigma" that may have been associated with borrowing from the IMF was being dissipated by the IMF's agreeing to play "a more active and perhaps more realistic role."

But the meeting ended without any firm conclusion on the methods by which the IMF and the World Bank would add to their resources. Bank President Robert S. McNamara, however, said at the final session that "bridging arrangements" had been completed this week with 14 countries to advance the International Development Association $1.2 billion to tide the soft-loan affiliate over until the current restocking of funds is completed.

These countries, by advancing part of their IDA pledges, will enable the agency to keep going while waiting on final ratification of appropriations by other countries that are laggard, notably the United States.

Coincidentally, at a meeting of private Saudi and American business leaders organized at the Treasury by Secretary G. William Miller, Saudi Minister of Finance Muhammad Abalkhail said the time had come for a U.S.-Saudi "partnership" going beyond the mere exchange of oil for goods and services.

His country, Abalkhail said, is determined to build an industrial capacity at a cost of $40 billion in the next five years. What is needed, he suggested, is a match-up of U.S. technology and know-how with Saudi capital and energy resources.

The IMF-Bank meetings were not disrupted, as some had feared, by Arab pressure to force the inclusion of the Palestine Liberation Organization as observers. Only the organizations which had been attending the meetings regularly were discomfited when all observers were disinvited as a temporary face-saving gesture for everyone.

Emile Van Lennep, director general of the Organization of Economic Cooperation and Development, for example, lost his basic credentials once the Interim and Development committees finished their work last weekend.

Lennep could obtain only a day pass, which did not give him access to the plenary sessions. "Lennep was so sore he could have exploded," a source said. p

Once again, the PLO question was passed on to a committee of governors, this time nine instead of eight in the hope of reaching a solution instead of the deadlock that had confronted these meetings.

Most delegates said privately that the PLO probably would be accepted at the next session, because there would be no election in the United States in 1981 and the U.S. would be unlikely to mount another exhaustive fight against the PLO. But American officials staunchly insisted that their anti-PLO position would not change.

The ninth nation added to the Board of Governors committee, due to report by Jan. 31, is Sweden, which so far has backed the U.S. view. That would appear to give the United States a 5-to-4 edge in the new committee.

Amir Jamal, the Tanzanian who chaired the joint session and who was a major force in trying to get the PLO included, reiterated in his closing remarks that the organization should be accepted.

"I also continue to hold the view," he said, "that at a time when the Bretton Woods institutions are under increasing pressure for change, the overt support from the PLO to them, by its readiness to associate itself with the Fund and the Bank, should be considered a welcome development."

De Larosiere stressed in final remarks that, in seeking to expand resources, the IMF will put the main emphasis on increased quotas (member deposits) as well as borrowing from rich member countries. Borrowing from the private markets is being considered but would be tried only after other alternatives have been exhausted.

He said that the IMF had not changed its decision, adopted at Hamburg earlier this year, not to sell any more gold but said that it would be inappropriate to use such words as "forever." He noted that if the IMF pledged never to make any more sales of gold, it would tend to give the yellow metal more importance than it deserves. The IMF owns about 100 million ounces.