President Reagan and White House chief of staff James A. Baker III today said that no decision has been reached on naming a new chairman for the Federal Reserve Board.

In addition, a senior administration official said that any such decision will not be forthcoming until at least next week and possibly "well beyond that."

The official added that more than two people are being considered for the post, despite reports that Alan Greenspan and Paul A. Volcker, the current Fed chairman, are the only remaining candidates.

Support for Volcker's reappointment in recent days has been building within the administration among Reagan's top economic advisers.

"All of that argument and speculation--we haven't even gotten around to making a decision yet," the president told television station KSTP here when asked if Volcker or Greenspan would get the job.

Baker today released a statement saying: "The president has made no decision on the chairman of the Federal Reserve Board. And a decision is not imminent."

In the TV interview, Reagan was asked if he feared that the money supply is growing too fast and could cause a new round of inflation. The president responded that, although stock markets have been "a little frightened by a surge there," he was not worried that there would be a persistent increase in the inflation rate.