The World Bank reported yesterday that it has under consideration applications from the Socialist Republic of Vietnam for subsidized loans to help rebuild the war-torn country.

A bank mission returned to Washington last week after spendiing about a month in Hanoi and elsewhere in Vietnam, and described its visit "as a useful and constructive start to the bank's relationship with unified Vietnam."

Bank sources said privately it is clear that the outlook for a loan is good. In a press release, itself an indication of a positive reaction by bank officials, Vietnamese officials were quoted as considering their country "to be part of an expanding international trading system."

Vietnamese leaders who met with the bank mission said they "look forward to constructive economic exchanges with all countries," according to the release.

The Socialist Republic of Vietnam was accepted as a member of the World Bank and the International Monetary Fund last fall, in place of the former Saigon government, over objections by the United States.

Sources said yesterday that the only major country that might have "a problem" approving a loan to Vietnam would be the United States until some progress is made on the question of accounting for Americans missing in action during the war.

"We haven't yet faced the specific decision of what we do about a loan to Vietnam, but our tendency would be to view lending to Vietnam on economic grounds, and to rely on international institutions," a Treasury Department official said. The United States could not block a loan to Vietnam without support from other nations.

The seven-member World Bank mission apparently was impressed by the Vietnamese government's success in meeting basic food needs, in part through imports. The country plans to expand agricultural production rapidly, aiming to achieve self-sufficiency in rice by 1980.

The loan applications are being considered by the International Development Association, the bank's soft-loan affiliate, which extends money at subsidized low interest rates of around 3 per cent.

Specifically, the Vietnamese officials asked to borrow money to develop irrigation systems in the Mekong Delta and for expansion of Northern Coal mines, with a view to building new export potential.

They also asked for assistance to expand their electyrc power system, mostly in the south, and to build a factory to manufacture railway cars, along with facilities for the maintenance of railway equipment.

One guess by World Bank official who stressed that it is very preliminary was that a loan in the range of $100 million to 200 million over 2 to 3 years might be considered.

The mission, which has given an oral report to the bank's board, is preparing a full analysis that the bank said would "be the basis of decisions" about loans to Vietnam.