WASHINGTON (Reuters) –
U.S. securities regulators on Monday charged a Michigan stock broker with fraud for allegedly luring seniors into a $250 million investment scam after convincing them to refinance their home mortgages.

The Securities and Exchange Commission alleges that Frank Bluestein acted as the single largest salesperson in a so-called Ponzi scheme operated by E-M Management, which was previously charged by the SEC with fraud in 2007.

Bluestein targeted potential investors who were retired or elderly and held investment seminars to lure them into investing in E-M securities. Bluestein also encouraged many of the investors to refinance the mortgages for their homes in order to fund their investments, the SEC alleged.

Calls to Bluestein's lawyer were not immediately returned.

(Reporting by Rachelle Younglai, editing by Gerald E. McCormick)