World Bank officials yesterday labeled the decline in their regular lending program in the past year a "temporary phenomenon," and projected new commitments to Third World borrowers of $40 billion to $45 billion over a three-year period.

But bank officials caution that making funds available at that level will require "political support" for greater resources for the bank.

The annual fiscal 1985 report for the International Bank for Reconstruction and Development showed that actual new loan commitments had dipped to just under $11.4 billion, compared with the IBRD's late 1984 estimate that the program would run between $12.6 billion and $13 billion. This was a decline of about $600 million from 1984, which officials attributed to a drop in domestic investment in the developing countries.

But for fiscal 1986, the World Bank has set an IBRD target of between $12 billion and $13.5 billion, and the three-year $40 billion-to-$45 billion goal implies a $14 billion to $15 billion average in 1987 and 1988. "We see solid lending prospects for the next three years," stimulated by a "turnaround" in investment interest in the Third World, World Bank Vice President D. Joseph Wood told a press conference.

Separately, concessional aid funneled through the International Development Association, a World Bank affiliate, dropped to $3 billion from $3.6 billion in 1984. The IDA program for fiscal 1986 also is budgeted at $3 billion. The longer-term outlook for IDA depends on future negotiations for the next IDA program, IDA-8.

Wood said that the IBRD should be "positioned" with resources and authority to lend at the upper end of the $40 billion-to-$45 billion range, including a general capital increase running for a five-year period. Member nations provide the increased capital, a small portion of which is paid in with the bulk available on a "callable" basis.

Wood and other officials, however, would not say how much of a general capital increase will be recommended by President A. W. Clausen when the question is presented to the joint IMF/Bank Development Committee in Seoul next month.

In an interview earlier this year, Clausen noted that the last capital increase in 1981 was $40 billion, and said "the next one ought to be at least that, and in my own mind it should be more."

But Clausen cautioned then that such an increase was not a certainty, and, in fact, several factors have come together in recent months that may lead to a more modest goal for the bank's new capital requirements. On an experimental basis, the bank's executive directors have just approved a pilot loan sales program of up to $300 million in existing World Bank loans. As these loans are made -- to commercial banks and institutional investors -- the bank's new capital requirements will be reduced by equivalent amounts.

Also, the 1985 lending shortfall of about $1.5 billion from projections removed some of the sense of urgency felt earlier to drive for a large general capital increase. In addition, the recently announced proposal for a multilateral investment guarantee agency, if it succeeds in encouraging the flow of foreign investment to lesser-developed countries, could take some pressure off the bank to boost its capital.

The annual report said that 1984 was a good year for developing countries "by the dismal standards of the early 1980s." But it pointed out that African countries continued to suffer declines in activity and that a new and growing threat of trade protectionism poses a threat to the Third World.

The World Bank, under pressure from Congress, also promised to give more attention to environmental considerations in approving loans. The report said that "degradation and destruction of environmental systems and natural resources are now assuming massive proportions in some developing countries, threatening continued, sustained development."

In a discussion of the future role of the World Bank -- which will be a topic of major debate at the meetings in Seoul -- the report said the bank must be "innovative," so that it can respond to changing economic conditions, but that it "should preserve and build on its traditional strengths, particularly in project design . . . "

In response to questions, Wood said the division of bank loans, with 15 to 20 percent going into so-called "structural adjustment loans" and the balance into projects, is expected to continue -- but not increase -- for the next few years. The structural adjustment loans (SALs) are quick-disbursing advances designed to ease economic stress, or to induce a change in a country's economic policy priorities -- for example, to stimulate exports -- rather than to finance a specific project. In the past few years, the bank has given more attention to SAL lending, which was begun in 1980.