The Student Loan Marketing Association said yesterday it wants to take over a Kansas agency that is in financial trouble because of a high number of defaulted student loans.

It would be the first time the association, known as Sallie Mae, has involved itself in guaranteeing student loans, and other guarantee agencies immediately charged the action would create anti-competitive pressures and conflicts of interest.

Sallie Mae's proposal to the Education Department is an ironic development in the search for a solution to the financial problems of the Higher Education Assistance Foundation (HEAF) of Overland Park, Kan., one of the largest student loan guarantors in the country. Sallie Mae, a federally chartered secondary loan market, has seen its stock price slip this week because it has extended $800 million in credit to the Kansas guarantor and purchased $2.4 billion of its guaranteed loans.

Sallie Mae said it is permitted to become a guarantor under its federal charter and has the financial resources and skills to manage HEAF's $9.6 billion portfolio.

"We are the only player in this business that has a billion-dollar net worth. That adds some confidence" to the federal loan program, said Lawrence A. Hough, Sallie Mae's new president and chief executive officer.

Hough conceded that Sallie Mae's charter restricts the circumstances under which it could take over the Kansas guarantor. "The secretary has got to ask us," he said, referring to Education Secretary Lauro F. Cavazos.

A trade group that represents student loan guarantors yesterday wrote the Senate Banking Committee to express "strong opposition" to the proposal.

But a committee hearing yesterday heard Hough and government witnesses say the impact on banks, the government and Sallie Mae would be minimal if HEAF becomes insolvent, as the Education Department expects.

In its letter to Patrick J. Lawler, chief economist for the Senate Banking Committee, the National Council of Higher Education Loan Programs Inc. charged that by becoming a guarantor, Sallie Mae would "combine all the functions of different {loan} program participants. . . in a single organization," creating "the potential for conflict of interest." The organization also charged Sallie Mae would assume "a dominant position" in the market.

The financially successful Sallie Mae, which has a AAA credit rating, has been trying to expand. It has played a leading role in organizing CollegeCredit, which would be a new source of student loans.

One guarantor that reacted favorably to the proposed takeover was the Kansas agency. "It does bring an institution with enormous financial resources to the problem," said Philip R. Rever, a HEAF vice president who runs its district office. HEAF is the designated guarantor for the District and five states and does business in most states.

In addition to the Sallie Mae proposal, the Education Department has discussed a HEAF takeover with United Student Aid Funds, a large guarantor based in Indianapolis, and with the Massachusetts Higher Education Assistance Corp., which wants to form a consortium of guarantors.

At the Senate Banking hearing, Education Undersecretary Ted Sanders estimated a takeover would cost the government less than $100 million.