City Managing Director Kirk Caldwell yesterday said he will run for mayor when Mayor Mufi Hannemann leaves office, be it 2010 or 2012.

Caldwell, 56, plans to hold a fundraiser this month; tickets for the event say he will run for mayor in 2012, when Hannemann's second and final term expires.

Hannemann has set up an exploratory gubernatorial committee, however, and many suspect he will resign as mayor next summer to run for governor. Caldwell said if that happens, he will throw his hat in the ring for mayor then.

Caldwell joins City Prosecutor Peter Carlisle and City Councilman Donovan Dela Cruz as announced candidates for mayor.

An attorney by trade, Caldwell has been Hannemann's appointed second-in-command since last summer. From 2002 to 2008, the Manoa resident had been a key player as a member of the Democratic leadership in the state House of Representatives.

Caldwell last year chose to forgo re-election to the state House of Representatives and tried to run for an open City Council seat, but his candidacy was ruled invalid because he had not resigned from his state House seat by the deadline.

Caldwell said he is concentrating his efforts on being managing director. "But I want to start early," he said of his mayoral bid. "You need to raise a lot of money. It's a lofty goal running for mayor. It's a huge race."

Caldwell said it's important to announce his intentions now to mobilize his supporters.

He would not be the first managing director seeking to replace his old boss. In 1994, Managing Director Jeremy Harris campaigned successfully for mayor when Mayor Frank Fasi resigned to run unsuccessfully for governor against Ben Cayetano.

Dela Cruz, 36, announced over the weekend his plan to run for mayor next year. Dela Cruz, who cannot run for re-election because of the council term limit, said he has no doubt that Hannemann will run for governor next year.

Carlisle, 56, also said he will run when Hannemann leaves the mayor's office.

Two other potential mayoral candidates told The Advertiser yesterday they are still weighing their political options: City Council Chairman Todd Apo and University of Hawai'i engineering professor Panos Prevedorous, who ran for mayor last year.