CSL completes Novartis flu vaccine deal

CSL says it has completed the $US275 million takeover that will allow it to form the world's second biggest flu vaccine company.

Biotechnology giant CSL has completed its $US275m acquisition of Novartis' influenza business. (AAP)

Biotechnology giant CSL has completed its $US275 million ($A376.1 million) acquisition of Novartis' influenza business.

CSL on Monday said it had paid cash for an acquisition that will allow it to create the world's second biggest company in the $US4 billion flu vaccine industry.

The company's shares soared to a new all-time high of $98.96 on Friday, when the company said it was bringing forward the close date on the deal which was first announced last October.