Shares of PharMerica were last quoted at $12.25, down 14.3%, on volume of more than 215,000, according to Nasdaq.com. Based on Friday's regular-session close at $14.30, the stock was up nearly 30% in the past year, hitting a 52-week high of $16.15 on Nov. 8. Earlier Friday, Omnicare, whose stock was off 1.4% in the extended session, announced it had extended its tender offer to purchase all outstanding shares of PharMerica for $15 each until Feb. 17. PharMerica has said in the past that Omnicare's bid undervalues the company and advised shareholders not to tender their holdings to the tender offer. Omnicare said that as of Thursday, roughly 4.7 million PharMerica shares had been tendered to the offer, roughly 16% of the company's outstanding stock. Omnicare first revealed its offer to buy PharMerica for $15 per share in late August, In a press release at that time, Omnicare said the all-cash bid was worth a total of $716 million, including assumption of debt, and that the consideration represented a premium of more than 35% to the previous session's closing price. "If Omnicare is allowed to purchase its biggest and only national competitor, it will diminish competition and raise health care costs -- leaving taxpayers and patients to foot the bill," said Richard Feinstein, Director of the FTC's Bureau of Competition, in a statement. "The Bureau will continue to be vigilant in our efforts to prevent these sorts of anticompetitive deals."