Treasury Secretary James A. Baker III yesterday rejected Third World demands for dramatic new shifts in global debt strategy and defended his own plan for dealing with the debt problem.

"There are no quick fixes that can solve the debt problem, and dramatic solutions won't appear overnight," Baker said in a speech to the Interim Committee, the policymaking board of the International Monetary Fund.

Meanwhile, the decision of the Group of Seven major industrial nations to continue to work for stability of exchange rates around current levels was "warmly endorsed" by the Group of Ten and by the Interim Committee, which will endorse the action in a communique today.

The G-7 countries are the United States, Japan, West Germany, France, England, Italy and Canada. The Group of Ten -- actually 11 -- adds Belgium, the Netherlands, Sweden and Switzerland.

All of these group meetings were held to prepare for the joint annual meeting of the 151 member countries of the World Bank and the IMF starting Tuesday.

At the annual meeting two years ago, the Treasury secretary introduced the Baker Plan for dealing with Third World debt. It called for new lending by multilateral and commercial banks and for economic reforms by borrowing countries to promote economic growth.

Baker yesterday cited "impressive progress" in solving debt problems that has been made by individual nations, among them Colombia, Mexico, Chile and the Philippines.

But he acknowledged that the recent trend of higher interest rates had complicated the problem for some borrowers, and said that his earlier suggestion of a "menu" of alternative options to traditional loans should be explored further.

Specifically, he called on the IMF to begin to play a bigger role in "growth-oriented programs" in the middle-income countries. He said he would elaborate on this suggestion when he addresses the annual meeting Wednesday.

In a second speech to the assembled finance ministers and central bankers at the day-long Interim Committee session, Baker said that "if remaining problems in the global economy are to be overcome," European countries must step up their economic growth rates.

He said international trade imbalances "remain large, and slow growth in Europe is a matter of concern, but particularly in the largest countries."

Baker painted a generally optimistic picture of prospects for a reduction in trade imbalances among the United States, Japan and West Germany, citing the fact that for three consecutive quarters the volume of U.S. exports has expanded.

His upbeat tone, both in terms of prospective global economic growth and the progress that he claimed had been made under the debt strategy he outlined two years ago in Seoul, stood in sharp contrast to a more desperate assessment by the Third World countries.

Brazilian Finance Minister Luiz Carlos Bresser Pereira, for example, who also spoke to the Interim Committee, challenged the Baker strategy.

Because "there is no medium-term prospect for a decline in market interest rates," he said, the commercial banks and debtor nations must agree on lower interest rate levels "compatible with the effective payment capacity of each country."

In order to avoid a public disagreement, Baker did not name West Germany as the target of his remarks on slow growth in Europe.

But he pointedly cited, with approval, plans being put in place by Japan and other countries to promote global growth.

For the most part, Baker and the other finance ministers have stressed the harmony that prevails, especially in their commitment to support exchange rates around current levels, as a basis for optimism on the global economic outlook.

A somewhat grimmer assessment of global prospects was expected from World Bank President Barber Conable, who addresses the joint meeting tomorrow. The annual reports of the bank and its private sector subsidiary, the International Finance Corp., have already forecast below-par global performance for the next year to 18 months.

Meanwhile, the bank announced yesterday that its concessional aid program managed for the poorest countries through its affiliate, the International Development Association (IDA), became operational last week when Japan put up an early deposit of $2.15 billion.

That advance for the program, known as IDA-8, along with early contributions from six other countries, will enable money to flow to projects that otherwise would have stalled while grants by other countries were awaited.

IDA makes loans of 35 or 40 years at no interest (but with a small service charge) to the poorest countries. The basic IDA-8 agreement is for $11.5 billion from 32 donors. About half of the IDA-8 money will go to Africa, with about 30 percent split between India and China.

Baker again outlined U.S. policy toward "enlarged access" to IMF funds, which allows needy countries to borrow up to 50 percent more than they normally would be permitted. The "enlarged access" policy was adopted as an emergency procedure when many countries began to run balance of payments deficits after the 1979 second oil "shock."

Baker said "a strong case can be made for a modest reduction in current access limits, but {we} are prepared to support a maintenance of current limits at this time on the understanding that the IMF will continue prudent implementation of access policy, and that we do not move in the near-term on Fund quotas."

There had been some discussion of a possible increase in the quotas, or deposits put into the institution by member nations.

The United States and some other nations believe the IMF already has adequate resources and any additional help should go to the World Bank.