Morgan Stanley, the second-biggest shareholder in New York Times Co., sold its entire stake today, according to a person briefed on the transaction, sending the stock to its lowest in more than 10 years.

New York Times shares slid 48 cents, or 2.5 percent, to $18.43 at 12:44 p.m. in New York Stock Exchange composite trading and fell as low as $18.28, a level not seen since January 1997.

Morgan Stanley held 10.5 million New York Times, or a 7.3 percent stake, as of June 30, making the company the second- largest institutional investor behind T. Rowe Price Group Inc., with a 14 percent stake.

Family members led by New York Times Chairman Arthur Sulzberger Jr. control the company through their ownership of Class B shares that allow them to appoint nine of the company’s 13 directors.