The campaigns of President Bush and Sen. John F. Kerry announced an agreement yesterday to hold three presidential debates and one vice presidential debate, and released a 32-page contract covering details ranging from permissible camera angles to height of the lecterns (50 inches).

The agreement embraced the schedule proposed by the Commission on Presidential Debates, calling for debates over two weeks beginning Sept. 30, with each lasting 90 minutes and beginning at 9 p.m.

The most contentious issue was an Oct. 8 debate that is to be held in a town-hall format, with audience members asking questions. Bush's chief negotiator, James A. Baker III, had proposed dropping that meeting because the president's advisers were concerned that partisans could pass themselves off as "undecided voters," as the commission's proposal described the audience.

The agreement Baker worked out with Kerry's lead negotiator, lawyer Vernon E. Jordan Jr., specifies that the audience consist of 100 to 150 "likely voters who are 'soft' Bush supporters or 'soft' Kerry supporters," split evenly between the two. The Gallup Organization will pick the audience, submitting its methodology to the campaigns for approval 14 days before the debate.

The Sept. 30 debate will be at the University of Miami in Coral Gables, Fla. The commission had proposed that it focus on domestic issues, but the agreement specifies that it cover foreign policy and homeland security. The town-hall debate will be at Washington University in St. Louis.

The last debate will be Oct. 13 at Arizona State University in Tempe and will cover economic and domestic policy. The vice presidential debate will be Oct. 5 at Case Western Reserve University in Cleveland.

-- Mike Allen and Dan Balz