The International Monetary Fund cut interest rates.

Interest on some of its loans has been lowered to 7% from 7.87%, retroactive to Nov. 1, 1985, the IMF said. The fund declined to say how much lending would be affected, but analysts estimated that Brazil and Mexico--the Third World’s biggest debtors--may save as much as $20 million a year. A statement by the fund said the reduction, which returns to the level charged before November, is being made because the fund’s income has improved with some overdue loans being brought up to date, expenses being cut and other interest rates having fallen.