Novartis sues Bayer over haemotology patent

ZURICH, Feb 20 (Reuters) - Swiss drugmaker Novartis AG (NOVN.VX) is suing Bayer AG (BAYG.DE) in the United States, saying the German company's Kogenate haemotology drug infringes a patent under U.S. law.

Novartis and Novo Nordisk A/S (NOVOb.CO) are seeking damages from Bayer -- as well as CSL Ltd (CSL.AX) unit CSL Behring for its Helixate medicine -- according to court documents filed by Novartis and Novo in a District court in Texas on Feb. 15.

"Defendants have purposefully and voluntarily placed one or more of their infringing products into the stream of commerce with the expectation that they will be purchased by consumers in the Eastern District of Texas," the filing said.

"These infringing products have been and continue to be purchased by consumers in the Eastern District of Texas. Defendants have committed the tort of patent infringement within the State of Texas and, more particularly, within the Eastern District of Texas," the court filing said.

Bayer shares were down 1.5 percent at 54.08 euros by 1233 GMT on Wednesday, when the DJ Stoxx European pharmaceuticals sector index .SXDP was down 1.2 percent.

Novartis's shares were 1.5 percent lower at 54.30 Swiss francs and Novo's were down 1.6 percent at 332.00 Danish crowns.

"While this adds to negative Bayer news of the last few days we don't see meaningful impact on numbers," Dresdner Kleinwort analysts said in a note. (Reporting by Sam Cage; Editing by Greg Mahlich)