For more than a year, Mayor Bloomberg has publicly denied that he is running for president. Meanwhile, Mr. Bloomberg’s own Web site is promoting the idea. Earlier this week, mikebloomberg.com sent its subscribers a link to an op-ed penned by Mayor Koch predicting Mr. Bloomberg would run.

“I believe that at the end of this year or in early 2008, New York Mayor Michael Bloomberg will announce that he’s running for president,” Mr. Koch wrote in the Washington Post.

While Mr. Koch said he had no “inside sources” telling him of a pending declaration, he noted that “it’s obvious that Bloomberg is doing everything a pro would do to prepare for a national run.”

A professor of public policy at Baruch College, Douglas Muzzio said the mere fact that a Bloomberg-sanctioned site is sending out news columns pontificating about whether he’ll throw his hat in the ring is part of the game the mayor is playing to keep interest going in his possible bid.

The Bloomberg Web site uses the same domain name the mayor used when he ran for office. It was relaunched as a personal site in May, looking very much like something a candidate would maintain.

The New York Observer’s political Web log also reported yesterday that mikebloomberg.com has taken out advertisements on Google’s e-mail sites.

A spokesman at Rubenstein Communications who represents the mayor on his nongovernment business, Robert Lawson, said: “The Web site links to many stories that highlight the mayor’s accomplishments both in and outside city government. An email alert was sent to those who signed up for regular updates to mikebloomberg.com when the story was posted on the site.”