Philippine President Ferdinand Marcos yesterday ousted the controversial president of the nation's central bank in the middle of crucial debt negotiations with both the International Monetary Fund and the Philippines' commercial bank lenders.

Marcos said that Jaime Laya, 45, had been "promoted" to Minister of Education, Culture and Sports. Several weeks ago Marcos turned down Laya's offer to resign after revelations that for many months the central bank had overstated the Philippines' foreign exchange reserves by about $600 million to make the country appear to be a better loan risk than it was.

Although the central bank's deception angered many of the Philippines' bank lenders, the major negotiating banks yesterday said they endorsed a Philippine request that it be permitted to postpone principal payments on debts that mature between Jan. 16 and April 16. A similar debt moratorium had been approved in mid-October and Manila's 450 bank lenders are expected to approve the new request.

The Philippines, beset by severe internal unrest after the assassination last fall of political opposition leader Benigno Aquino, has about $24 billion of foreign debt. Bankers said yesterday that it is not clear how much of that outstanding debt will be affected by the two repayment moratoriums, although it is at least several billion dollars.

The Philippines has requested an additional loan of $1.6 billion from its bankers, but the banks have said further negotiations on that loan, as well as negotiations on a formal restructuring of about $10 billion of Philippine debts--which started coming due in October 1983 and will continue to come due until early 1985--should be put off until the Marcos government reaches an agreement with the International Monetary Fund.

The IMF has a team in Manila now and sources said the international financial rescue agency hopes to reach a loan agreement with the Philippines--which will require the country to take stern austerity measures--within three weeks.

Laya, who has headed the central bank for six years, two weeks ago called 1983 a year of disaster for the Philippine economy. He was one of the first Philippine officials to say publicly that the Aquino assassination had hurt the nation's economy. Investors had been pulling dollars out of the Philippines during most of 1983 because of the political unrest and hastened the process after the assassination.