Massachusetts' chief securities regulator has hit top Wall Street firms with subpoenas, saying he fears elderly people are being targeted for high-risk, alternative investment products.

Massachusetts Secretary of the Commonwealth William F. Galvin said on Wednesday subpoenas have gone out to a group of firms including Morgan Stanley, UBS AG, Fidelity Investments, Bank of America Corp.'s Merrill Lynch, Wells Fargo & Co., TD Ameritrade and Charles Schwab Corp.

Galvin said a recent investigation into real estate investment trusts heightened his concern that elderly investors were being targeted with products too complex for them to understand the underlying risks.

"While these products are not unsuitable in and of themselves, they are accidents waiting to happen when they are sold to inexperienced investors by untrained agents who push the products to score the large commissions associated with alternative investments," Galvin said in a press release.

The subpoenas seek information about the sale of the products to seniors in Massachusetts, and regarding supervision, compliance and training at the firms, Galvin's office said. Alternative investments cited by Galvin included REITs, oil and gas partnerships and private placement offerings.

In May, Galvin's office announced a settlement with five independent broker-dealers who agreed to pay at least $9.6 million in fines and restitution to settle what regulators called their improper sales of non-traded REITs.

Among the companies named on Wednesday, spokespeople for Bank of America and Morgan Stanley declined to comment. A Wells Fargo spokesman said via e-mail that "The only statement we have at this point is that our policy is to cooperate fully with our regulators."

Representatives of the other companies did not immediately respond to questions.