Former Pennsylvania Sen. Rick Santorum announced Tuesday the formation of an exploratory committee to run for the GOP nomination for president in 2012.

Santorum made the announcement on Sean Hannity's radio show, saying he has filed paperwork with the Federal Election Commission to establish what he calls a "candidate committee." This filing is one step closer to a formal declaration of candidacy for the former senator, who created a "testing the waters" committee in April that was not required to file with the FEC.

"I am pleased that we have taken this important next step in the process to potentially become a candidate for President of the United States," Santorum said in a statement.

With this exploratory filing, Santorum has qualified to participate in the first Republican presidential debate--sponsored by Fox News and the South Carolina Republican party--in Greenville, South Carolina Thursday.

"The debate this Thursday is a unique opportunity to put forth ideas and solutions to bring our economy back on track, and with Osama bin Laden's death, I look forward to also discussing in depth ways to tackle our many national security challenges," Santorum's statement reads.

April Girouard and Cherie Grzech contributed to this report.