The Icahn Group announced yesterday that shareholders of Dan River Inc. had agreed to sell it about 836,080 shares, which gives the group nearly 30 percent of the common stock of the Danville, Va., textile manufacturer.

At the same time, the group, headed by New York investor Carl Icahn, announced it was extending its tender offer of $18 a share for Dan River stock from Wednesday to midnight next Tuesday. Dan River management, which strongly opposes Icahn, could not be reached for comment last night.

On Tuesday, the Dan River board of directors met in New York to discuss a management proposal calling for the company's 12,000 employes to acquire the stock. There was no comment by the company following the meeting.

The management plan, which a spokesman had described as extremely tentative, would have employes pay $22.50 a share, or a total of $130.5 million, for all of Dan River's common stock.

Last month Dan River arranged to sell about 475,000 shares of its common stock to McDonough Co., a U.S. unit of the British textile firm Hanson Trust PLC. This move generally was viewed as a defensive measure against the Icahn Group, which includes Icahn Capital Corp., C.C.I. & Associates and Crane Associates.