UPDATE 2-Daiichi to buy German cancer firm U3 for $234 mln

(Adds details on U3 investors, background on previous deals)

By Taiga Uranaka and Ben Hirschler

TOKYO/LONDON May 21 (Reuters) - Daiichi Sankyo Co Ltd (4568.T) has agreed to buy privately owned German biotech firm U3 Pharma AG for 150 million euros ($233.5 million) to boost its pipeline of cancer drugs.

The Japanese drugmaker said on Wednesday the acquisition would give it a variety of early-stage fully human antibody programmes with potential for treating breast, lung, colorectal and other cancers.

The deal highlights an increasing drive by pharmaceutical companies in Japan to tap into overseas biotech expertise and build up their presence in cancer treatment -- the fastest-growing section of the global pharmaceuticals market.

"One of our goals for Daiichi Sankyo is to increase our presence in novel therapeutics in the oncology arena," Takashi Shoda, the company's president and CEO, said in a statement.

"Our acquisition of U3 Pharma is an ideal strategic fit."

Its purchase of the small German start-up follows larger acquisitions of promising foreign cancer businesses by rivals.

Takeda Pharmaceutical Co Ltd (4502.T) agreed last month to buy Millennium Pharmaceuticals Inc MLNM.O for $8.8 billion, while Eisai Co Ltd (4523.T) struck a deal to acquire MGI Pharma for $3.9 billion in December.

U3 Pharma was established in 2001 by Axel Ullrich of the Max Planck Institute of Biochemistry and employs 27 people, most of whom work directly in research and development.

Its most advanced anti-cancer product, U3-1287 (AMG 888), is being co-developed with Amgen Inc (AMGN.O) and is due to enter clinical development this year.

Daiichi Sankyo said this portfolio dovetailed with its own oncology pipeline, which includes three human monoclonal antibodies in development and a joint research venture with another German antibody specialist, MorphoSys AG (MORG.DE).

Daiichi Sankyo also has a cancer drug called CS-1008 in mid-stage Phase II tests for malignant neoplasms and the rights to sell Amgen's Phase III bone drug denosumab in Japan.

U3 Pharma's investors include Alta Partners, Atlas Venture, E. de Rothschild Investment Partners, Life Science Partners and Karsten Henco. (Editing by Will Waterman)