President Carter today will make proposals to key congressional leaders designed to avert a looming White House veto of the controversial Federal Trade Commission authorization bill.

Opponents of the bill say it would cripple the agency by limiting its authority to set guidelines for business operations and monitor alleged monopoly practices. Both House and Senate versions of the legislation also would cut short current FTC investigations dealing with proposed limits on television advertising aimed at children and on price disclosure by funeral homes. They also would end any FTC authority over agricultural cooperatives and the insurance industry.

Among the key provisions of the administration proposal to be presented to the nine invited members of a House-Senate conference committee considering the bill is one that would maintain the FTC's hotly disputed investigation of television advertising directed at children, sources said.

Administration sources and others stressed that Carter is deeply committed to maintaining in any bill most of the powers that would enable the FTC to continue as an effective agency.

Sources said that pieces of the current administration position were presented to consumer and labor group leaders and FTC officials, including Chairman Michael Pertschuk, at a White House meeting late yesterday.

The meeting yesterday was said to focus on an effort to rally the FTC's long-time supporters in the consumer and labor movements behind the administration proposal. In addition, the meeting was an attempt to assure that the administration wouldn't be the target of political criticism after possible presidential signing of compromise legislation.

"The president does not want a confrontation with the conferees," said one White House official. "He does not want confrontation for confrontation's sake. There are clearly strong feelings on both sides. But the president is prepared to take a strong stand."

There appears to be general agreement among FTC supporters that although they feel the Carter package ultimately will harm the agency, their support may be the only way to avert a presidential veto of sweeping provisions that virtually would kill a sseries of FTC cases.

Several consumer group sources said after the meeting that they would support the presidential package and work diligently to block congressional efforts to overturn a Carter veto of any FTC bill the administration could not support.

"It's not pleasant," said one FTC supporter. "But this is the best we can do. The package does a little bit of damage to everything."

Several of these sources blasted the on-going House-Senate conference process. Conference comittee members have been holding secret meetings during which dramatic changes in the House and Senate bills have been worked out. "The whole thing up there (on Capitol Hill) has been flagrantly undemocratic," one activist said.

A congressional source, in remarks typical of those heard from FTC advocates, including White House staffers, predicted that if Carter vetoes a bill produced by the conference, "The FTC is gone." The well-placed source said the agency would lose not only ongoing cases, but also vital and experienced staff members.

Administration officials have been saying for some time that Carter might sign an FTC bill containing a legislative veto provision if it didn't kill ongoing FTC cases. Sources said such a bill could be acceptable to Carter with the current proposal for a two-House legislative veto. The provision would allow Congress to block any FTC rule-making.

The precise administration response to House opposition to the FTC's funeral rule-making remained unclear late yesterday, although Carter administration officials are attempting to work out language that won't gut the case, but also would include a provision granting a state-regulated funeral homes immunity from FTC scrutiny.

Administration officials appear ready to recommend acceptance of the House provision on the children's television advertising case. This provision wouldn't effect that case, but would limit the FTC's power to regulate advertising.

Sources say the administration may accept a proposal that would continue the FTC's so-called Sunkist case, which involves monopolization charges against the giant California citrus cooperative.