Mayor Michael Bloomberg will launch Thursday a coalition of mayors and business leaders to advocate for an overhaul of the nation's immigration policy, including legalizing undocumented immigrants and more strictly fining businesses that hire illegal workers.

"Our immigration policy is national suicide," Mr. Bloomberg said at a forum in Midtown Wednesday. "We educate the best and the brightest and then we don't give them a green card—we want people to create jobs but we won't let entrepreneurs from around the world come here."

During his latest inaugural address, Mr. Bloomberg vowed to push to rework the nation's immigration laws in the same way that he waged battle against illegal guns. This effort will be a cornerstone of the mayor's third-term agenda, aides said.

The coalition, the Partnership for a New American Economy, supports developing a secure system for employers to verify employment eligibility and strict penalties for businesses that fail to comply. The group wants to increase opportunities for immigrants to enter the workforce and for foreign students to stay in the country.

The group will advocate for securing the nation's borders and beefing up enforcement to prevent illegal immigration. The coalition supports establishing a legal path for the millions of undocumented immigrants living in the country now.