Peru's major bankers have devised an eight-year, $880 million loan package to keep the Latin American nation financially afloat for the next 12 months.

The package, which was put together by 10 major Western banks advising Peru, needs the approval of the other 255 banks that hold Peruvian debt.

Bill Rhodes, Citibank's senior vice president in charge of Latin American lending, said the other banks will be asked to refinance $430 million of Peruvian loans that come due by next March. He said the banks will be asked to lend an additional $450 million to the country.

Peru, which owes foreign creditors $11 billion, was one of the first Latin American nations to have trouble repaying its international loans. It negotiated with its bankers last year and entered into a three-year rescue agreement with the International Monetary Fund.

IMF officials are said to have told Peru's banks that they must continue to support Peru to keep the IMF involved.

Rhodes, who is chairman of the 10-bank advisory committee, said that, in addition to the $880 million loan, banks also will be asked to keep up the $2 billion in short-term credit outstanding to the Latin American nation.

Under the package proposed yesterday, Peru will pay interest on the $880 million loan, but will not have to begin repaying the principal until 1986. The country then proposes to pay off the $880 million in 11 semiannual installments.

In the last nine months, many Latin American nations have had to refinance their foreign debts, tighten their belts and go to the IMF for aid--including Mexico, Brazil, Argentina and Chile.

Rhodes said that were it not for the severe difficulties in other Latin American countries--which have made banks wary of lending to that part of the world--Peru probably would have been able to borrow the $880 million on its own.

Peru, like other developing countries, was hit hard by the worldwide recession. Both demand and prices for commodities which those countries export dropped sharply.

The decline in oil prices should help most developing countries by stimulating a recovery in the developed countries that are markets for exports of nations like Peru.