Starboard Value, a New York-based activist hedge fund, said it bought a stake in office supplies retailer Staples and increased its stake in rival Office Depot.
Shares of Staples and Office Depot rose sharply Thursday morning.
The disclosure was made to the Securities and Exchange Commission on Wednesday. Starboard said it bought a 5.1 percent stake in Staples and increased its stake in Office Depot to 9.9 percent from 8.6 percent.
Starboard has a history of buying stakes in companies and shaking them up. Recently, the New York-based hedge fund successfully pushed Darden Restaurants, the owner of Red Lobster, to remove its board of directors. Starboard did not say in the filing if it had any plans for Staples and Office Depot, and it did not immediately respond to a request for comment.
Staples and Office Depot did not immediately respond to a request for company. Late last year, Office Depot and OfficeMax combined in a $1.2 billion deal.
Shares of Staples Inc., based in Framingham, Massachusetts, rose $1.28, or 8.6 percent, to $16.09 in morning trading Thursday. Shares of Office Depot Inc., based in Boca Raton, Florida, rose 71 cents, or 10.5 percent, to $7.43.