For the second time in three weeks, Treasury Secretary James A. Baker III stunned financial markets, already in a frenetic state, with a statement on the dollar that suggested -- without being explicit -- that the United States is letting the dollar fall.

In a story based on an interview with Baker, the Wall Street Journal said that "the Reagan administration's top priority is to avoid a recession caused by high interest rates, even at the risk of a falling dollar." The headline was: "James Baker Stresses Holding Down Rates Even if Dollar Suffers."

Treasury sources said that the headline overstated what Baker said, but did not deny the basic thrust of the story, which was that administration dollar policy had now shifted. Instead of focusing on stabilizing the dollar, the emphasis now -- according to the story -- is on easier monetary policy, even if that means a decline in the dollar.

Baker apparently made an effort yesterday to assure his counterparts in West Germany and Japan that the United States is not advocating a "free fall" of the dollar, and that he anticipates meeting with the Group of Seven finance ministers later on for new discussions on policy coordination. A free fall would involve a plunge of the dollar, out of control, with no visible brakes available to stop it.

Baker also arranged for the White House, which had confirmed the interview as administration policy, to issue a follow-up statement saying: "The United States remains committed to the Louvre agreement and will continue cooperating closely with its G-7 partners to foster exchange rate stability." The Louvre agreement is an international pact aimed at stabilizing currencies.

Despite what appeared to be efforts to soften the hard edges of the Journal story -- which included criticism by "administration officials" of the Fed's half-point boost in the discount rate in September -- Wall Street and business analysts elsewhere interpreted Baker's latest statement on the dollar as a risky venture.

"This is a step of last resort," said New York investment banker Geoffrey Bell. "If you don't really have a policy, you say, 'I will allow my currency to depreciate.'

"It may work out well, because the United States needs a lower dollar to correct its trade deficit. But it's odd that Baker would spend almost 10 months defending the dollar rate, then pick a time of instability like this to allow the dollar to fall."

Bell said that "the great danger" in the new policy as he understood it from the Wall Street Journal is that if the administration and Congress fail to come up with a convincing package of deficit reductions, there might be a "free fall" of the dollar, forcing interest rates up, and eventually leading to a recession.

Another prominent Wall Street executive, who declined to be identified, said, "Baker is playing with fire. I worry about the view that we can smash the dollar down. That's a very dangerous exercise."

Stephen Marris of the Institute for International Economics, who had been predicting a rapid fall for the dollar culminating in a recession, said that the new policy "is a recipe for disaster." Marris said that any country that chooses to devalue its currency must also accept a dose of austerity.

"This is a strange action for a country that needs to borrow $10 billion to $15 billion a month to pay its foreign debts," he said. Marris also suggested that Baker's criticism of the Federal Reserve's move to raise interest rates last September "adds to the aura of no confidence."

On the weekend before Black Monday on Wall Street, Baker caused consternation when he sharply criticized West Germany for its high interest rate policy, and said that the United States would not match German interest rates in an effort to prevent the dollar from falling.

Baker denied then that his intent was to signal an active American policy to push the dollar down. Nonetheless, his comments -- which gave high visibility to the discord between Bonn and Washington in a basic economic area -- has been cited by some as one reason for the 508-point decline in the Dow Jones industrial average on Oct. 19.

Sources indicate that the West Germans are still bitter about the way in which Baker singled them out for criticism. As recently as Wednesday, West German Finance Minister Gerhard Stoltenberg said that Baker had made a mistake in doing so.

None of Baker's colleagues among the Group of Seven finance ministers had any advance knowledge of what he would tell the Journal, a source said. In a telephone interview from Frankfurt, where he is attending a private conference, economist C. Fred Bergsten said that "I think that communications {among the ministers} is at a low point."

Until his remarks just before the Oct. 19 stock market collapse, Baker had enjoyed widespread praise for his role in establishing a new and closer form of economic cooperation among the leading financial powers.

In September 1985, Baker reversed the Reagan administration's commitment to a high and overvalued dollar. At a meeting of the finance ministers of the United States, Japan, West Germany, France and Britain at the Plaza Hotel, he initiated a policy of market intervention to push the dollar down.

By February of this year, those powers, with the addition of Canada, decided to call a halt to the dollar decline at the Louvre Palace in Paris. Although reaffirmed twice by the Group of Seven, which also includes Italy, the Louvre Accord did not succeed in reducing the American trade deficit or cutting the German and Japanese surpluses.

Moreover, the stabilization of exchange rates was achieved only through higher interest rates in this country -- a factor that Baker said in the Journal interview had contributed to the market plunge.