Longs Drug Stores Corp.'s largest institutional shareholder, Advisory Research Inc., said it will support CVS Caremark Corp.'s $2.7 billion takeover offer.

Advisory Research, which owns 9.2 percent of Longs, is disappointed Walgreen Co. withdrew its $2.8 billion bid on Wednesday, President David Heller said yesterday.

The firm said in a statement yesterday it will tender its shares in favor of CVS's cash offer.

Longs Drug directors spurned the Walgreen bid because they thought it posed antitrust risk.

Longs has 41 locations in Hawaii, including another two in construction.

The purchase values Longs at $71.50 per share and gives CVS, the second-largest U.S. chain, 521 stores, for a total of 6,800. The acquisition gives CVS a foothold in Hawaii, Nevada, Arizona and California. Longs is based in Walnut Creek, Calif.