The former mayor filed papers to create the Rudy Giuliani Presidential Exploratory Committee, Inc., establishing a New York-based panel that would allow him to raise money to explore a White House run and travel the country. The four-page filing, obtained by The Associated Press, lists the purpose of the non-profit corporation "to conduct federal 'testing the waters' activity under the Federal Election Campaign Act for Rudy Giuliani." The paperwork, dated last Friday, is signed by Bobby Burchfield, a partner at the DC-based law firm of McDermott Will & Emery, a firm that handles political work. "Mayor Giuliani has not made a decision yet," Giuliani spokeswoman Sunny Mindel said in a statement Monday night. "With the filing of this document, we have taken the necessary legal steps so an organization can be put in place and money can be raised to explore a possible presidential run in 2008."

One potential rival for the GOP nomination, Sen. John McCain of Arizona, said Sunday he was taking the initial step of setting up an exploratory committee. Under federal election law, an exploratory committee allows an individual to travel and gauge the level of support for a candidacy without formally declaring themselves a candidate and adhering to all the federal rules of fundraising. An individual who spends money only to test the waters - but not to campaign for office - does not have to register as a candidate under the election law.

The GOP field is expected to grow with Massachusetts Gov. Mitt Romney, Sen. Bill Frist of Tennessee, Arkansas Gov. Mike Huckabee and New York Gov. George Pataki expected to join the presidential fray. Democratic Gov. Tom Vilsack of Iowa has filed to establish a full-blown campaign committee and will make a more formal announcement of his candidacy later this month.

Giuliani was widely praised for leading the city during and after the terror attacks of Sept. 11, 2001. He has said for months that he would wait until the end of the 2006 elections to decide whether to embark on a White House bid. The former mayor is a moderate who supports gun control, same-sex civil unions, embryonic stem-cell research and abortion rights - stands that would put him at odds with the majority of the GOP conservative base.