Pharmacy-benefits manager Express Scripts said it was starting a $25 billion exchange offer for all outstanding shares of rival Caremark Rx , despite drugstore operator CVS' bid for the company.
CVS said on Nov. 1 it planned to acquire Caremark for about $21.2 billion in stock. Express Scripts launched its bid for Caremark on Dec. 18.
Under terms of the exchange offer, Express Scripts will offer $29.25 in cash and 0.426 shares of stock for each share of Caremark. Based on Friday's closing stock prices, the company said its bid represents a 7% premium over the current CVS proposal.
Caremark's board has voted against Express Scripts' offer.
The exchange offer will expire Feb. 13. Caremark said it was taking the action "in light of the Caremark Board's rejection of and refusal to even discuss our superior proposal."
"CVS remains committed to closing its merger with Caremark in the first quarter of 2007," a company representative said.
Caremark had no immediate comment on the exchange offer.