Digital Realty Trust Inc. raised additional net proceeds of about $9.7 million in its series K preferred stock offering.

The data center real estate investment trust said the underwriters in the offering partially exercised their overallotment option to buy 400,000 additional shares of its 5.850% series K cumulative redeemable preferred stock in a transaction that close March 15. The underwriters were granted an option to acquire up to 1.2 million additional shares.

Merrill Lynch Pierce Fenner & Smith Inc., Morgan Stanley & Co. LLC and Wells Fargo Securities LLC represented the several underwriters in the offering.