Brazil and its bankers yesterday formally signed agreements that will pump $4.4 billion into the financially troubled country this year and permit Brazil to put off repaying $4 billion in debts that come due in 1983.

Citibank and Morgan Guaranty Trust Co., in a joint announcement, said the debt agreements are conditioned on International Monetary Fund approval of an additional $4.88 billion in rescue funds. Brazilian officials are expected to sign an agreement with the IMF on Monday.

Brazil, which has more than $80 billion in outstanding debts, will be able to draw $2.5 billion of the new loan by March 15 and equal installments of $633 million in June, September and December.

There were 169 banks around the world involved in the $4.4 billion loan, and 672 banks agreed to postpone repayments due in 1983. Brazil will pay interest on both the new loan and the postponed repayments but will not begin repaying principal for 30 months. Both agreements call for repayment in full in eight years.

On Thursday, Mexico reached an agreement with its 530 bankers on a new $5 billion loan to carry that country through 1983. The International Monetary Fund already has signed a three-year, $3.9 billion assistance package with Mexico.

Earlier this year, Argentina renegotiated its debts with its bankers. Several other developing countries, including Venezuela, are having trouble meeting their debt payments because the worldwide recession has caused a sharp decline in price and demand for their exports.

Mexico and Venezuela are major oil exporters who may face more difficulties in the months ahead because prices appear poised for further declines.

Last Monday Venezuela suspended all foreign currency operations to conserve its dwindling international reserves and put in a two-tier exchange rate to prevent capital from leaving the country.

Venezuelan officials are expected to come to New York next week to begin negotiations with their bankers on a deferment of some loans that come due in 1983. They are expected to approach the IMF for assistance as well.

Brazil went to its bankers last December with a request for the new loans and the postponement of repayments due in 1983. The country also asked for continued trade financing as well as a commitment from the banks to hold their short-term lines of credit for Brazilian banks at the $9.2 billion level that existed on June 30, 1982.