June 21 (Bloomberg) -- Two U.S. lawmakers asked the Securities and Exchange Commission to postpone Blackstone Group LP's initial public offering until Congress holds hearings.

Representatives Henry Waxman, a California Democrat who chairs the House Oversight Committee, and Dennis Kucinich, said in a letter to SEC Chairman Christopher Cox today that the IPO may present ``investors and the public with new and undisclosed risks.''

Blackstone's offering is scheduled to price later today. The company, a private-equity partnership based in New York, plans to raise as much as $4.75 billion.

Under the Securities Act of 1933, the SEC can block an initial public offering only over concerns that a company's filings with the agency contain inaccurate or incomplete information or makes untrue statements. SEC spokesman John Nester declined to comment while U.S. stock exchanges were still open.

Waxman's panel is the lead congressional body that monitors and investigates the executive branch of government. Kucinich is an Ohio Democrat who's seeking the party's 2008 presidential nomination.

To contact the reporter on this story: Jesse Westbrook in Washington at jwestbrook1@bloomberg.net.

Last Updated: June 21, 2007 16:02 EDT