Legislators averted a confrontation over a federal bailout for the ailing Farm Credit System (FCS) by agreeing to a compromise that gives two other House committees a chance to review work of the Agriculture Committee before the measure is given full consideration by the House.

After Reps. John D. Dingell (D-Mich.) and Fernand J. St Germain (D-R.I.) raised strong objections last week, a bitter clash was expected on the House floor yesterday over a section of the bill that would provide federal guarantees for a secondary market in which farm real estate loans could be bought and sold.

House leaders backed away from the showdown by agreeing to allow committees headed by the two lawmakers to conduct their own hearings and suggest changes to the secondary-market section of the bailout legislation.

Dingell, chairman of the Energy and Commerce Committee, and St Germain, chairman of the Banking, Finance and Urban Affairs Committee, protesting that the Agriculture Committee measure did not provide sufficient regulatory protections for investors, insisted on being allowed to offer amendments to the FCS bill.

The House, meanwhile, took up less controversial amendments yesterday and decided to adjourn early so that committee Chairman E. (Kika) de la Garza (D-Tex.) could depart for his district to take part in a celebration today of his 60th birthday.

The farm credit measure, though depicted by de la Garza and other agriculture leaders as urgent, apparently will not return to the House calendar until Oct. 7 at the earliest, when the Energy and Banking committees must return the secondary-market section to the floor.

Leaders of the FCS, which holds about a third of the nation's farm debt, have insisted that they must have federal assistance before the end of the year to avoid a collapse of the debt-plagued system.

The bailout measure sent to the floor by the Agriculture Committee did not specify an amount or source of federal assistance. But an amendment approved by the Rules Committee for presentation on the floor by de la Garza would provide $2.5 billion to the farmer-owned lending network in fiscal 1988.

The money would be raised by the sale of unspecified Farmers Home Administration assets -- presumably water and sewer loans and possibly land in the FmHA foreclosure inventory.

"This is quick money, an infusion," de la Garza told reporters yesterday. "We figure we need a quick transfusion for the balance of 1987 and early 1988."

De la Garza said that after the $2.5 billion is expended, future federal assistance would have to be provided as needed by the FCS through the usual appropriations process.

The Senate Agriculture Committee is scheduled to meet Wednesday to continue marking up its own version of a bailout bill that is expected to require, like the House measure, major liberalizing changes in FmHA operating procedures.