Japan's largest drugmaker Takeda Pharmaceutical Co is in talks to buy privately-held Swiss rival Nycomed in a deal that could be valued at about $14.2 billion, Bloomberg said, citing two people with knowledge of the matter.

Negotiations are at an advanced stage and a deal could be announced as early as next week, Bloomberg reported. No agreement has been reached yet and the talks could still fall apart, the news agency said.

It is our policy not to comment on market rumors about business development activities, said Takeda spokeswoman Hisako Nagata.

Japanese drugmakers, including Daiichi Sankyo and Astellas Pharma, have been actively pursuing acquisitions to boost growth as they face the loss of patent protection on key medicines and struggle to develop hit drugs on their own.

Takeda bought U.S. biotech firm Millennium Pharmaceuticals for about $9 billion in 2008 and has said it would be willing to take on debt for future deals.

Nycomed, which is controlled by Nordic Capital and Credit Suisse Group AG's private-equity unit, would help broaden Takeda's reach in emerging markets, Bloomberg said.

(Reporting by Renju Jose in BANGALORE and James Topham in TOKYO; Writing by Anshuman Daga; Editing by Lincoln Feast)