Biopharmaceutical company Immunex ( IMNX) said Friday its public offering of 70 million common shares has been priced at $39.75 a share. The stock sale will raise about $2.7 billion for Immunex and its partner, American Home Products ( AHP). Of the shares offered, 20 million are newly issued by Immunex. American Home Products will offer 50 million shares from its holdings of Immunex common stock, as well as offer underwriters an over-allotment option of up to 10.5 million additional shares. Immunex will not receive any proceeds from the sale of shares by American Home Products. Immunex says it will use its share of the proceeds to finance expansion of its manufacturing capacity and build a new research and technology center in Seattle. The funds may also go towards acquiring other businesses, products and technologies. Shares of Immunex were recently climbing 1.42%, or 56 cents, to $40.38 in Nasdaq trading Friday, while American Home Products gained 0.52%, or 31 cents, to $60 in New York Stock Exchange trading.