Japan's Takeda Pharmaceutical Co is in talks to buy privately-held Swiss rival Nycomed, which has a significant presence in Europe and emerging markets, in a deal that could be worth more than 1 trillion yen ($12 billion), two sources told Reuters.

Japan's biggest drugmaker has already approached a number of major lenders to help finance the deal, the sources said.

The scale of this buyout is really large. We still don't know the exact details of the deal and the company (Nycomed), but Takeda has carried out this kind of strategy for a long time, said Hiroaki Osakabe, a fund manager at Chibagin Asset Management.

Takeda and Nycomed declined to comment. Takeda, which has long been keen to boost its reach in Europe, has previously said it would be willing to take on debt for future deals.

Nycomed would be a second major deal for Takeda after it bought U.S. cancer drug specialist Millennium Pharmaceuticals in 2008 for about $9 billion.

A $12 billion purchase would be the second-biggest takeover by a Japanese firm after Japan Tobacco's $19 billion purchase of British rival Gallagher, according to Thomson Reuters data.

Sources told Reuters Takeda had hired Deutsche Securities as an advisor. One source said that the deal was in its final stages. Another said that Takeda is talking with several megabanks about financing and that the banks were prepared to lend the money if an agreement was reached.

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.

Takeda's shares shed 1.4 percent, in line with the Nikkei benchmark index.

Nycomed, which has 12,500 employees, is majority owned by four private equity firms, led by Nordic Capital with a 41 percent. The other three are Credit Suisse's DLJ Merchant Banking which owns 25.6 percent, Coller International Partners with 9.7 percent and Avista with 8.9 percent.

Nycomed's top product is pantoprazole for heartburn, a field that Takeda knows well with its own Prevacid, a former blockbuster heartburn drug that has now lost patent protection.

The mid-sized pharmaceutical firm with 12,500 employees also boasts lung drug roflumilast, known as Daxas in Europe and as Daliresp in the United States. It is the first drug in a new class of treatment for chronic obstructive pulmonary disease, a common and deadly disorder which causes breathing difficulties and is often caused by cigarette smoking.

It won U.S. approval in March, following earlier delays, where Forest Laboratories has the marketing rights. In Europe, Merck & Co has the marketing rights.

It has been the subject of much speculation about a sale or an IPO, with the Wall Street Journal reporting in 2009 that the drugmaker had hired Goldman Sachs to explore a possible sale of the company, a deal that was said at the time to be worth as much as 10 billion euros.

Chief Executive Hakan Bjorklund told Reuters earlier this year that an IPO this year was highly unlikely.

Takeda said on Wednesday that it expects operating profit to increase 6.2 percent to 390 billion yen in the year to March 2012, helped in part by sales of its top selling diabetes drug Actos.

But it expects operating profit to fall to 240 billion yen two years later, hurt by the expiry of its patent on Actos. Chief Executive Yasuchika Hasegawa said, however, he expects that to be the bottom.

We will continue to pursue the acquisition of rights to drugs in late-stage development and the acquisition of companies. From experience, I expect we will be able to return to the earnings levels seen in the last business year by the year ending March 2016, he told a news conference.

Nycomed had revenue of 3.2 billion euros in 2010 and generated earnings of 774.9 million euros before interest, taxes, depreciation and amortization. Emerging markets accounted for 39 percent of its revenue, with sales in Latin America up 29.8 percent and sales in Russia up 23.3 percent.

Last year, Nycomed bought a majority stake in a Chinese pharmaceutical company, underscoring its focus on emerging markets and Western manufacturers' hunger to boost their presence in the country.

It paid around $210 million for the 51.3 percent stake in Guangdong Techpool Bio-Pharma. ($1 = 81.065 Japanese Yen) (Writing by Edwina Gibbs; Additional reporting by James Topham, Junko Fujita, Ritsuko Shimizu and Antoni Slodkowski in TOKYO and Renju Jose in BANGALORE; Editing by Anshuman Daga)