Australia's CSL Ltd (CSL.AX), the world's largest blood products company, said on Monday it had agreed to buy Novartis AG's (NOVN.VX) global influenza vaccine business for $275 million.

Combining the Novartis unit with CSL subsidiary bioCSL would great the No.2 player in the $4 billion global influenza vaccine industry, CSL said in a statement to the Australian stock exchange.

CSL said it would fund the deal with surplus cash and estimated integration costs at $100 million, while synergies were seen at $75 million a year by 2020.