A consortium backed by activist hedge fund Starboard Value LP has offered roughly $9 billion to buy department store Kohl’s Corp. , according to people familiar with the matter.

A group led by Acacia Research Corp., which Starboard controls, offered to buy the department-store chain for $64 a share in cash Friday, the people said. It told the company it has received assurances from bankers that it would be able to get financing for the bid, the people said.