UPDATE 1-Glaxo buys Argentine drugmaker for $253 million

* Buying Argentina’s Laboratorios Phoenix in cash deal

* Acquisition reinforces build-up in emerging markets

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LONDON, June 10 (Reuters) - GlaxoSmithKline GSK.L stepped up its drive into emerging markets on Thursday with the acquisition of Argentina's Laboratorios Phoenix for $253 million.

The cash transaction -- the latest in a string of deals in developing markets -- gives the British-based drugmaker a portfolio of branded generics covering therapeutic areas such as cardiovascular, gastroenterology, metabolic and urology.

Phoenix also brings Glaxo a factory near Buenos Aires, a primary care sales force and pipeline of additional branded generic medicines. (Reporting by Ben Hirschler; editing by Paul Sandle)