The head of one of Columbia University’s financial aid offices is being investigated for recommending a student loan company to borrowers at the same time as he held stock in the company, the state attorney general’s office and Columbia said yesterday.

A senior associate dean of student affairs at Columbia, David Charlow, owned 7,500 shares of Education Lending Group Inc., according to records on file with the federal Securities and Exchange Commission. The company is the parent of Student Loan Xpress, which Columbia recommends to students as a “preferred lender.”

Investigators with Attorney General Andrew Cuomo’s office sent Columbia a subpoena yesterday as well as inquiry letters to the University of Southern California and the University of Texas at Austin, whose aid officers are also being investigated by Mr. Cuomo for owning stock.

Mr. Charlow profited more than $100,000 from the sale of the 7,500 shares and an additional 2,500 in stock warrants, according to the attorney general’s office.

The stock ownership disclosure comes in Mr. Cuomo’s widening investigation of the $85 billion student loan industry.

A woman who answered Mr. Charlow’s telephone at Columbia said he wasn’t available.

A campus spokesman, Robert Hornsby, said in a statement that Columbia “promptly” began its own investigation and told the attorney general after it learned that one of its officers had a potential conflict of interest with one of its preferred lenders.

Mr. Hornsby said a financial aid official had been placed on leave pending the outcome of the investigation.

Representatives of the University of Southern California and Education Lending Group didn’t immediately return phone calls seeking comment.

A spokesman for the University of Texas, Don Hale, said the university was investigating the matter.

Mr. Cuomo has charged that big lenders in the financial aid industry give kickbacks to universities as well as gifts and trips to school employees in exchange for placement on “preferred lender” lists.