The South Korean government reportedly made a new offer of assistance yesterday to American officials probing the Korean influence-buying scandal. The offer came as the House of Representatives unanimously approved a resolution condemning South Korea for its failure to cooperate.

The Haptong News Agency in Seoul reported that South Korea is now willing to arrange for U.S. questioning of Korean businessman and socialite Tongsun Park in a neutral country about his role in the alleged bribery scheme.

A week ago, after Justice Department investigators had failed in an effort to negotiate terms for questioning Park, the department said Korea had rejected neutral country proposals.

Hapton said Korea's foreign minister, Park Tong Chin, had offered the neutral country compromise in a meeting with U.S. Ambassador Richard L. Sneider yesterday.

The announcement came before yesterday's unanimous House vote on the resolution, but House approval had seemed certain since the resolution was introduced last week.The resolution, sponsored by all 12 members of the House committee investigating the influence-buying scheme, asserts that the South Korean government was responsible for the program, and that the traditional alliance between the United States and South Korea might be damaged if Seoul fails to cooperate in the American investigation.

Tongsun Park, who has been indicted on charges of conspiracy and bribery in connection with the Capitol Hill influence buying effort, was one target of the House investigation, but sponsors made it clear yesterday that they also want information about Korean government officials allegedly involved in the scheme.

During, debate on the resolution yesterday, two Californians, Democrat Charles H. Wilson and Republican Charles E. Wiggins, expressed skepticism about the extent of Korea's operations of Capitol Hill. Other members seemed to have no doubt about the resolution's suggestion that the Seoul regime was responsible.

Debate on the measure was routine except for one potentially dramatic moment. But the drama quickly fizzled. Rep. Edward J. Derwinski (R-Ill.), who is suspected by the Justice Department of tipping off South Korea when a Korean agent here was about to cooperate with House investigators, announced that he would speak on the resolution.

A quorum call was arranged so that members could be present to hear Derwinski. About 300 came to the floor, apparently believing that he woudl have some comment on the allegations against him. But Derwinski mentioned that charges - the subject of a grand jury investigation - only in passing during a five-minute address stressing the need for a strong South Korean army to resist aggression from communism.

The resolution, passed 407 to 0, will have no substantive effect on American aid to or agreements with South Korea. But it serves as an additional warning to Seoul that its traditionally warm reception by the U.S. Congress has chilled because of the influence buying scandal.

Last week a key committee chairman said the President Carter's newest military aid proposal for Korea could not pass the House if it were brought to the floor now.