But the campaigns said no to a formal offer outlined in a letter from Bloomberg and ABC on Sunday envisioning a 90-minute primetime broadcast moderated by Diane Sawyer to kick off the town hall series in New York City. The campaigns said the candidates intend to make the town hall meetings open for broadcast on all television networks or on the internet, rather than sponsored by a single network or news organization.
Bloomberg, the billionaire mayor who toyed with mounting his own independent presidential bid this year, has sought to hold onto the spotlight that began to fade after he declared in February that he would not run for the White House.
A spokesman for the mayor indicated that Bloomberg is not giving up his attempt to have a role in the town hall meeting process.
"We're committed to finding a similar format that works for a joint town hall meeting between the two candidates in the nation's largest city," Stu Loeser said.
ABC did not immediately comment.
Bloomberg and ABC News President David Westin had proposed that the first meeting take place at Federal Hall in Manhattan. McCain had already suggested the venue, where George Washington took his oath of office as the country's first president.
In their letter sent Sunday to the candidates, Bloomberg and Westin said the date and other details - like how much interaction the candidates would have with voters or a moderator - would be worked out between the two campaigns.
When Bloomberg said he had decided not to make a third-party White House bid, he vowed to stay engaged in the process - and hinted that he might put his wealth and support behind one of the contenders.
The Democrat-turned-Republican-turned-independent has said he is not necessarily most likely to back the candidate who matches his policy positions, but the one who demonstrates the most genuine bipartisan credentials.
Bloomberg supporters have also pushed the idea that he could be a running mate for either candidate, although neither McCain nor Obama seems to match that enthusiasm for picking him.
---- Associated Press Writer Nedra Pickler contributed to this story from Chicago
