The World Bank, in a major shift in policy, is reading plans to lend $450 million in "risk capital" over the next five years to less developed countries to explore for oil and natural gas.

While still viewed as controversial by some senior U.S. officials, and quietly opposed by anumber of mahoroil companies, the Exploration loan program is expected to be approved Jan. 16, when the World Bank board votes on a proposed $3 billion, five-year oil and gas development loan program.

In addition, the bank is also expected to approve a $340 million, five-year coal development program at the January meeting, according to informed sources.

Details of the proposal are laid out in a World Bank proposal, which is now being circulated to its 20-member board of directors and which was obtained by The Washington Post.

The question of whether the bank should be involved in promoting development of oil and gas in the less developed countries-and in particular high-risk oil exploration ventures-has been the subject of running and occasionally heated debate since the idea was first promoted after world oil prices quadrupled in 1973. Rapid oil price increases, and the economic slowdown that followed in the industrial countries, had a devastating effect on many of the Third World countries who were not members of the Organization of Petroleum Exporting Countries.

In domestic energy circles, the somewhat controversial proposal to have the World Bank help Third World countries indirectly compete with some major oil companies has become a political symbol of U.S. determination to stimulate the development of non-OPEC sources of oil.

The 35-page proposal says that "investing in petroleum exploration is inherently riskier than in conventional Bank projects." The document, however, goes on to argue that by loaning seed money, and by acting as the so-called honest broker between host countries and international oil companies, the bank can play a positive role in stimulating oil development in the Third World. This in turn, would lower the severe financial burdens posed by high oil prices tha thave hamstrung many Third World countries.

The result of the loan program, the bank proposal says, is that it "is likely to attract oil companies to invest capital for exploration in a wider range of countries."

Supporters of the bank's oil and gas loan program, which includes funding for geological exploration, wildcat drilling, and funds to develop known resources, say there is enormous untapped potential of new oil production form about 50 less developed countries in Latin America, Africa, and Asia. World Bank energy experts say this potential may be equal to, or larger than, the Alaskan and North Sea oil fields combined.

With the exception of the exploratory drilling, the bank's other oil and gas loans or credits are categorized as low risk.

Nearly two-thirds, or about $2.07 billion, of the bank's loans and credits would go toward developing known oil and natural gas reserves in oil-importing countries. These loans, which in many cases would be "seed" money to go with other funds borrowed at commercial terms or invested by foreign companies, would go torward developing resources that otherwise would have not been developed.

An additional $460 million would be made available for so-called "appraisal drilling" -sinking wells to delineate known fields of oil and gas to determine whether the deposits can be developed economically.

The bank has also earmarked about $102 million for geophysical and geological surveys, which are the first stage of oil and gas developement.

Earlier this year the World Bank issued projections saying that the less-developed non-OPEC countries, now producing about 3.8 million barrels a day could produce 8.5 million by 1985, and 10.4 million by 1990.

If these goals are met, and the Bank energy loan program is successful, as many as 50 or more Third World countries could become self-sufficient in oil production by 1990.

Countries engaged in active discussion with the bank for exploration and development loans include: Chad, Bolivia, Zaire, Egypt, Tunisia, Turkey, Syria and Colombia.

Prior to fiscal 1978 all of the bank's loans for energy were confined to pipelines-classified as transportation-or assistance to build electrical generation plants. Since July, however, the bank has lent$189 million, including $150 million for developing India's Bombay High Fields.

In addition to laons the bank would make at standard though below market rates, energy development credits would be made available to poorer Third World countries through the bank's International Development Association (IDA, in the form of "soft loans."

World Bank experts in the past have said that in some cases, with half a billion dollars in seed-money loans, Third World countries would be able to attract an additional $3 billion to $4 billion from international capital markets or from private oil companies.

One successful example of such a program, is a Nov. 14 agreement signed between Gulf Oil Corp., Pakistan, and the Pakistan Oil and Gas Development Corp. The bank reviewed contract proposals from Gulf and from the Pakistanis, and said that it would consider extending a development loan to Pakistan if significant quantities of oil and gas are found.

"The possibility of bank participation in other arrangements of this kind is under discussion in a number of countries," the proposal says.

The World Bank's energy package, considered by many participants as one of the bank's most innovative and potentially most effective undertakings in years, is the product of intensive negotiations that peaked at the Bonn Economic Summit last July, when the heads of the industrial countries agreed to press the development of Third World energy resources.

Informed sources say that the position the United States takes at the bank's January meeting chaired by its president, Robert S. McNamara, will be key to whether the proposal is approved.

U.s. reluctance to support the expanded oil and gas program, and in particular the loans for exploration, had been centered in the Energy Department where some mid-level policymakers argued that by funding exploration the bank could produce an unnecessarily high demand for drilling rigs.

DOE policy-makers, however, have recently decided to support the bank proposal. The remaining resistance to the exploration loans is now limited to the Treasury Department, where some policy-makers have reservations about whether the bank should lend funds for risky projects.

Treasury Secreatary W. Michael Blumenthal has yet to make a decision, but knowledge able sources say that the United States will likely support the proposal in its present form.

Some major oil companies, including Exxon, have expressed private concerns to U.S. officials, saying the bank's program is not needed, and that the only obstacles to drilling in the Third World are the host countries' political uncertainties, and the lack of prospects for oil concessions the companies prefer. They also argue that there are better prospects for drilling elsewhere.