A House subcommittee asked the Justice Department yesterday to look into possible perjury by top officials of the Federal Emergency Management Agency and the acceptance of gratuities by the agency's director, Louis O. Giuffrida.

In a report on its year-long investigation of alleged fraud and mismanagement at the agency, the panel also accused Giuffrida of improperly intervening in agency contract awards and asked him to repay $5,091 for agency-funded trips to Europe and Mexico by his wife.

The report by the House Science and Technology subcommittee on investigations and oversight, chaired by Rep. Harold L. Volkmer (D-Mo.), comes one day after FEMA announced that Giuffrida has resigned, effective Sept. 1. The report, which the subcommittee adopted unanimously, was released eight months after the Justice Department began to investigate the disaster planning agency.

FEMA spokesman Robert Mahaffey said he was still reviewing the report and had no comment.

In the most serious new allegation, the report cited six instances in which one witness' testimony "directly conflicted" with another's at subcommittee hearings.

One instance involved what the report described as the acceptance of gratuities by Giuffrida and Fred J. Villella, formerly the agency's No. 3 official. Villella, who resigned last August, has said he did nothing improper.

The report noted that Giuffrida, Villella and their wives attended a $250-a-plate reception for Vice President Bush last year as guests of Triton Corp., then a major FEMA contractor. After Triton executives took Giuffrida and Villella to the affair at the National Republican Club, the company billed FEMA for the tickets.

Giuffrida and Villella and their wives also attended a $120-a-plate dinner honoring President Reagan at Triton's expense. The subcommittee is referring the matter to the Justice Department.

Giuffrida told the panel he did not know who paid for the Republican Club tickets. He said Villella had received the invitation and told him that "we are going to be somebody's guests and there will be no charge to us." But Villella testified that he could not recall the discussion.

Giuffrida also testified that he was never told that Triton had billed FEMA $2,000 for the tickets. But this was contradicted by former FEMA inspector general Robert Goffus, who testified that the matter had been "brought to the attention of Mr. Giuffrida's staff, and to the best of my recollection to the director himself."

The report recommended a federal audit of Triton's contracts with FEMA. In 1983, it said, agency officials ordered that Triton's vouchers be sent directly to the FEMA comptroller for payment, bypassing normal review procedures. When a project officer questioned the vouchers, the report said, the agency downgraded his performance rating.

"Payments of Triton vouchers were put on a special system of 'Pay now, question later,' " the report said, clearing the way for a "large number of questionable billings."

Triton officials have defended their billings as proper. They say they inadvertently charged FEMA for the Republican Club tickets and later reimbursed the government.

The subcommittee criticized Giuffrida's role in two contract proposals. In one case, the report said that "Giuffrida improperly exerted the influence of his office in an effort to gain agency approval" of a $100,000 FEMA grant to the International Management and Development Institute to study emergency preparedness. Giuffrida sits on an institute committee.

Four months before the institute applied for the grant to study emergency preparedness, Giuffrida wrote the institute's chairman that "we intend to provide support . . . in an amount not to exceed $100,000."

The panel said Giuffrida had "a conflict of interest" with a second contract proposal from an Arlington firm to computerize a FEMA data bank that was already computerized. Giuffrida had discussed the proposal with an old Army associate who works for the company.

Two FEMA employes testified that they were ordered to approve the proposal by top Giuffrida aides Frank Payne and Ronald Face. Payne and Face denied giving such orders. The contract was never awarded.

On other issues, the report said:

*There was "insufficient" reason for FEMA to pay the first-class airfare for Giuffrida's wife, Genevieve, to accompany her husband on an 18-day trip to Europe and a five-day trip to Mexico City. Giuffrida should reimburse the government $5,091, unless he can convince the General Accounting Office that his wife's travel was business-related.

*Part of a dormitory at FEMA's emergency training center in Emmitsburg, Md., "was renovated to provide a permanent, private residence" for Villella, who then headed the center. The improvements included an $11,000 stove, wet bar, microwave oven, fireplace and cherrywood cabinets.

"There is overwhelming evidence that all of the questioned items originated with Villella or Giuffrida, both of whom must bear the responsibility for the waste of over $70,000 of government funds," the report said. It said the questioned changes were "unrelated" to the original renovation contract.

*The Justice Department should seek reimbursement from Villella for work on the training center's chapel for his daughter's 1982 wedding. Electrical work and the installation of lights to allow videotaping were done "solely for the purpose of enhancing the chapel for the wedding of Villella's daughter."

*Villella accepted two nights of free accommodations at the Hotel Del Coronado in San Diego and "made a false statement" about it on his travel voucher, saying he had "stayed with friends." Villella later arranged for the hotel to be used for a FEMA conference, but the conference was canceled and the hotel is seeking reimbursement from FEMA.