JOHN McCAIN has decided on his running mate, according to Republican strategists.

He is expected to reveal his choice at a rally at a basketball arena in Dayton, Ohio, at 11am on Friday.

Senator McCain's decision is known only to his small inner circle of advisers, no more than three or four people, who have refused all public discussion on the matter. Republicans close to the campaign said that the top contenders remained the same three men who have been the source of speculation for weeks: former governor Mitt Romney of Massachusetts, Governor Tim Pawlenty of Minnesota and, possibly, Senator Joseph I. Lieberman, independent of Connecticut.

It was unclear how seriously Senator McCain was considering his good friend Lieberman, who favors abortion rights and whose selection could set off a revolt among delegates at the Republican National Convention next week in Minneapolis as well as a furious backlash among Christian conservatives, a crucial voting bloc of the Republican Party. But as recently as Tuesday, Senator McCain was said to still be entertaining the idea of Senator Lieberman, who was Al Gore's running mate on the Democratic presidential ticket in 2000.