One of seven Democratic senators just back from Panama said yesterday he now supports the canal treaties, while another was still not sure.

Sen. Howard Metzenbaum of Ohio said a six-hour meeting with panamanian chief of state Omar Torrijos had left him "prepared to ratify, barring some unforeseen, new developments."

Sen. Donald Riegle of Michigan said, "I'm still reserving final judgment but I feel much better about aspects of the treaty than I did before I went down there."

The two, in a group of undecided lawmakers led by Democratic leader Robert C. Byrd (W.Va.) who went to panama last week, were interviewed on NBC's Today program (WRC).

Byrd later told reporters that he still is uncommitted, but that statements made by Torrijos have "certainly improved the climate for the treaties" and "have opened the way for freer public discussion."

"I want to gain more knowledge and information before I make up my mind," he said. "I do not want to rush it. I want to carefully analyze the proposals."

An aide to Byrd said that the senator met with President Carter on Monday to discuss the Panama trip, and that the other six senators also may be summoned to the White House.