San Francisco-based private equity firm Vector Capital announced today that it has made an unsolicited offer to acquire Captaris, for $4.75 per share. The deal is worth approximately $125.4M. Captaris is a Bellevue, Wash.-based provider of document management software. Vector Capital owns approximately 10.2% of Captaris. Captaris said Monday that it has hired RBC Capital Markets to represent the firm; RBC has replaced Credit Suisse as its investment banker.