Commerce Secretary Malcolm Baldrige predicted yesterday that President Reagan's new trade initiatives will begin to reduce the trade deficit by next year, but he declined to say by how much.

"A month ago, I would have estimated the same deficit as this year or perhaps slightly lower for 1986 ," Baldrige told reporters. "Now I would estimate that it will go down lower than that."

The administration rushed out its new trade initiatives during the past three days to blunt bipartisan protectionist pressures from Congress, which has made job losses caused by record-high trade deficits into the politically potent issue of the moment.

Current projections call for the U.S. trade deficit to total a record $150 billion this year, and Baldrige acknowledged that any reduction as a result of the new administration program would be slight. He added it would be "ridiculous" to predict how much the deficit would be cut since an improved U.S. trade position depends on many factors -- including how far the dollar declines, how much the economies of other countries improve and whether the U.S. can reduce its budget deficit.

"I don't think we can get a turnaround in a matter of months. The forces involved are too great," Baldrige said.

The administration's new trade policy combines tougher talk on unfair trade practices that hurt American exporters and encourage a flood of cheap imports with an agreement among leading industrialized nation for coordinated intervention to lower the value of the dollar.

Baldrige, who consistently has fought within the administration for a tougher trade policy, called the Reagan program "a home run," and said it "includes everything that I would have recommended. I think the program is a winner."

The Commerce secretary described the coordinated action on the dollar, announced Sunday after a meeting in New York of finance ministers and central bank heads of the United States, Japan, France, West Germany and Britain, as the key element in the administration program.

He estimated that the dollar needs to fall 25 percent from its value last week -- before the new trade initiative. The value of the dollar stabilized yesterday and regained some ground slightly against most major currencies after dropping about 5 percent Monday, its largest decline in more than a decade.

There were some doubts, however, over how much intervention would be acceptable to the Reagan White House, which with its free market philosophy consistently has opposed moving in financial markets to lower the value of the dollar.

"If the administration decides to intervene in a major way, it would be a major turnaround, a colossal flip-flop equivalent to the president backing a tax increase," commented Sen. Bill Bradley (D-N.J.).

There were no indications, meanwhile, that the presidential trade initiatives succeeded in stopping the protectionist bill that is the most likely to win quick congressional passage, a measure that would protect American textile makers from foreign competition. Its main Senate sponsors, however, added a new component giving protection to U.S. shoe makers and softening its effect on Third World textile suppliers.

The measure, which faces a possible Senate filibuster, could come up as a amendment to other legislation due before the Senate this week.