Laboratory supplies maker VWR (VWR)  will be purchased by New Mountain Capital (NMFC) - Get Report subsidiary Avantor in a deal with an enterprise value of $6.4 billion. The firm's bid of $33.25 per share was 2.3% lower than the company's closing price on Thursday, resulting in a 2.3% decline for the stock in premarket trading Friday. 

VWR's stock is up nearly 17% this week after reports first surfaced of this possible deal earlier this week, which pushed the stock's price above New Mountain's purchase price. The stock is up more than 36% year to date.