Millennium Pharmaceuticals


announced that it will acquire

Cor Therapeutics

(CORR) - Get Report

in a stock deal worth $2 billion.

The agreement, approved by the boards of directors of both companies, will give Cor shareholders 0.9873 share of newly issued Millennium stock in exchange for each Cor share. Based on Wednesday's close, this would value each share of Cor at $35, a 77% premium.

Millennium expects to add four Cor directors to its board of directors after the deal has closed.

Shares of Cor were up 47% to $29 in premarket Instinet trading, while shares of Millennium were losing 13% to $30.80.