The debate over the presidential debates continued yesterday, as aides to President Reagan and Walter F. Mondale failed to reach agreement.

"We don't think we made as much progress today as we did" Thursday, White House Chief of Staff James A. Baker III said after the hour-long session, the third such meeting in eight days.

The two sides tentatively have agreed to at least one nationally televised presidential debate. Mondale has sought as many as six, while White House aides have indicated that they desire no more than two.

Mondale campaign chairman James A. Johnson said after the meeting yesterday, "I don't think either side is prepared to agree to anything until there's a whole package."

That package would include format, length and timing of the presidential debates, as well as possible debates between Vice President Bush and Mondale's running mate, Rep. Geraldine A. Ferraro (D-N.Y.).

Mondale favors a more "open" format with perhaps a single moderator asking questions and with more opportunity for follow-ups and give-and-take, but Reagan prefers a more structured and formal situation, such as questions from a panel of reporters.

While Reagan campaign aides would prefer to have any debates completed a month before the Nov. 6 election, Johnson said yesterday that Mondale favors at least one debate "after the World Series" ends, around Oct. 17.