Takeda Pharmaceutical Co <4502.T>, Japan's largest drugmaker, is buying privately held Swiss rival Nycomed for $13.6 billion, giving it access to a newly approved lung-disease drug, which is expected to be a major source of revenue growth.

The deal marks the biggest overseas purchase by a Japanese company since Japan Tobacco <2914.T> paid $19 billion for Britain's Gallaher and is Takeda's second major deal after acquiring U.S. cancer specialist Millennium Pharmaceuticals for $8.8 billion in 2008.

Takeda, known for its top-selling diabetes drug Actos which faces the upcoming expiry of its U.S. patent, will also gain a portfolio of over-the-counter consumer products.

The deal will help it expand in Europe and emerging markets and provide an immediate increase in stable cashflow.

In the long-term, this is a strategic fit. The question of how to strengthen their presence in emerging markets is one that all major drug firms face, said Atsushi Seki, pharmaceuticals analyst at Barclays Capital.

But in terms of Takeda's goal to return to last year's earnings level by the year ending March 2016, I don't think this deal quite gets them to the point where they are filling in the gap left by Actos' patent expiry.

Nycomed is well-placed to tap emerging markets, which made up nearly two-fifths of its revenue in 2010 and should make up 60 percent of sales by 2015. Emerging markets sales leapt 30 percent last year.

The deal lifts Takeda's global ranking to No. 12 from No. 16, Takeda said.

Other Japanese drugmakers have also been active in acquisitions in recent years.

Daiichi Sankyo <4568.T> acquired a majority stake in Indian generic drugmaker Ranbaxy for $4.6 billion, while Astellas Pharma Inc <4503.T> bought OSI Pharma for $4 billion and Eisai <4523.T> purchased MGI Pharma for $3.9 billion to boost their cancer drug pipelines.

The 9.6 billion euro payment is inclusive of Nycomed's net debt and Takeda will pay cash, financing part of that with a 600-700 billion yen ($7.3-$8.5 billion) loan. The deal, which excludes Nycomed's U.S. dermatology business, had been expected after being flagged by sources last week.

Nycomed...gives us an immediate strong presence in the high-growth emerging markets while doubling Takeda's European sales, Yasuchika Hasegawa, Takeda Chief Executive said in a statement on Thursday.

Takeda said the deal would result in an increase in annual revenue of more than 30 percent and an increase in annual operating income, excluding special factors derived from the acquisition, of more than 40 percent.

Zurich-based Nycomed is majority owned by four private equity firms, led by Nordic Capital with 41 percent. Credit Suisse's DLJ Merchant Banking has 25.6 percent, Coller International Partners 9.7 percent and Avista 8.9 percent.

Its lung drug roflumilast, known as Daxas in Europe and Daliresp in the United States, is the first in a new class of treatment for chronic obstructive pulmonary disease, a common breathing disorder often caused by smoking.

After some delays, it won U.S. approval in March where Forest Laboratories has the marketing rights. In Europe, Merck & Co has marketing rights.

Deutsche Bank acted as financial advisor to Takeda while Goldman Sachs and Credit Suisse acted as financial advisors to Nycomed.

Takeda's shares ended 0.5 percent higher ahead of the statement in a Nikkei benchmark <.N225> down 0.4 percent.

Takeda has also unsuccessfully explored takeovers of other European drugmakers previously, including Organon and Sweden's Meda AB , according to sources.

($1 = 0.707 euros, $1 =81.775 Japanese Yen)

(Additional reporting and Writing by Edwina Gibbs; Editing by Anshuman Daga)