(NYT107) NEW YORK -- Sept. 11, 2003 -- 9-11-ANNIVERSARY-4 -- Mayor Michael Bloomberg of New York during ceremonies at ground zero marking the second anniversary of the terrorist attacks on Thursday, Sept. 11, 2003. (Ruth Fremson/Pool/The New York Times)

(NYT6) NEW YORK -- Sept. 28, 2004 -- NY-MOVIES -- Actor and director Mel Brooks, center, reacts, as New York City Mayor Michael Bloomberg, left, and New York Governor George E. Pataki, look on, Tuesday, Sept. 28, 2004, at Steiner Studios, a 15-acre site at the historic Brooklyn Navy Yard, during a press conference announcing new incentive programs to promote film and televison production in New York. The 280,000-square-foot facility will be New York City's first Hollywood-style production and support facility. (Ruby Washington/The New York Times)

PHOTO: EAST NEWS/SIPA PRESS 26 August 2003 - Israel- Mayor Michael Bloomberg visits Hadassah Hospital, Ein Kerem during a solidarity visit to Israel. 00479136

(NYT43) NEW YORK -- June 28, 2002 -- NY-BLOOMBERG-FLOATER-- Mayor Michael R. Bloomberg shaking a fellow subway rider's hand as he and Gov. George E. Pataki, right, take the subway to Yankee Stadium Friday to see the boys of summer at work, the Yankees at play with the Mets. (Mike Nagle/The New York Times)

(NYT1) NEW YORK -- Jan. 15, 2003 -- NY-SCHOOLS-BLOOMBERG -- Mayor Michael Bloomberg delivers an address on education at the New York Urban League's Reverend Dr. Martin Luther King, Jr. Symposium, Wednesday, Jan. 15, 2003 in New York. Bloomberg proposed that every low-performing school in New York use a single uniform curriculum. The speech was Bloomberg's most wide-ranging address on education since he won control of the city school system last summer. (Librado Romero/The New York Times)

31 December 2011 - New York, NY - New York City Mayor Michael Bloomberg and pop superstar Lady Gaga teamed up to lead the crowd in the final countdown to midnight in Times Square on New Year's Eve in New York City. Photo Credit: Aaron Showalter/Sipa USA *** NY Newspapers Out***/gagablommberg.006/*** NY Newspapers Out***/1201011905

PHOTO: EAST NEWS/AFP New York mayor Michael Bloomberg kisses the Western Wall, Judaism's holiest site, 26 August 2003 in Jerusalem. Bloomberg is on an eight-hour visit to Jerusalem to meet victims of last week's suicide bomb attack.

PHOTO: EAST NEWS/SIPA PRESS "Literacy Partners" works in NYC teaching adults basic reading,writing & math skills:Michael Bloomberg,media billionaire who may run to be the next mayor of NYC 00426203

(NYT11) NEW YORK -- Nov. 25, 2001 -- NY-BLOOMBERG-PROFILE -- For most of his 59 years, there have been two distinct sides to Michael R. Bloomberg, the mayor-elect. Those who know him well say that New York City should expect to see plenty of both. There is the jocular, brash and egocentric Bloomberg. There is also the thoughtful, earnest and selfless Bloomberg. Interviews with his friends, relatives and business associates suggest that each version is authentic and irrepressible and that one is never too far removed from the other. Bloomberg underneath the Brooklyn Bridge in a recent photo. (Fred Conrad/The New York Times)

**FILE PHOTO** (NYT53) NEW YORK -- June 19, 2007 -- BLOOMBERG-2 -- Mayor Michael R. Bloomberg delivers his State of the City address in New York in this Jan. 17, 2007 file photo. Bloomberg announced on Tuesday, June 19, 2007, that he was quitting the Republican Party and had changed his affiliation to independent. (Andrea Mohin/The New York Times)

(NYT11) NEW YORK -- Jan. 6, 2003 -- REPUBS-CONVENTION -- Mayor Michael Bloomberg gets the call informing him that New York had been selected to host the 2004 Republican national convention while he was taking part in the inauguration of a winter festival at Lasker Ice Skating rink in Central Park, Monday, Jan. 6, 2003. Looking on are Parks Commissioner Adrian Benape and New York Tourism Director Cristyne Lategano Nicholas. (James Estrin/The New York Times)

PHOTO: EAST NEWS/SIPA PRESS New York - NYC mayoral republican candidate Michael Bloomberg casting his vote early in the morning at the Lillie Devereaux Blake School on 82nd Street between Park and Madison Avenue. 00426203

30 August 2010 - New York , NY - NYC Mayor Michael Bloomberg at the 2010 US Open Opening Night Ceremony held at USTA Billie Jean King National Tennis Center. Photo Credit: Brian Zak/Sipa Press/open_bz.021/1008310513

New York mayor Michael R. Bloomberg talks to reporters in Dubrovnik, Croatia, Friday, Dec. 3, 2004. Bloomberg arrived in Dubrovnik to present New York City's bid for the 2012 Olympic and Paralympic Games to the General Assembly of the European National Olympic Committees (EOC). (AP Photo/Darko Bandic)

PHOTO: EAST NEWS/SIPA PRESS New York - Billionaire media mogul Michael Bloomberg (center) celebrates with outgoing NEw York Mayor Rudy Giuliani and New York Gov. George Pataki after winning the New Jork mayoral race. 00426203