Japan's Suntory brings in 1st outsider to lead family firm to global growth -sources

* Takeshi Niinami to take up post on Oct. 1 - sources

* Niinami currently chairs convenience store chain Lawson

* Transitional year as Suntory beds in $16 bln Beam purchase (Adds background on Niinami, Suntory's goals, other details)

By Ritsuko Shimizu

TOKYO, June 24 (Reuters) - Family-owned Suntory Holdings Ltd will appoint its first outsider president, two sources familiar with the matter said, as the century-old Japanese drinks maker accelerates plans to transform itself from local champion to global giant.

Takeshi Niinami, chairman of convenience store operator Lawson Inc, will become president of the Osaka-based company on Oct. 1, the sources said on Tuesday. The appointment comes as Suntory beds in the $16 billion acquisition of Beam Inc, owner of Jim Beam bourbon and other brands, that made it the world's third-biggest spirits maker earlier this year.

Niinami is new to the dedicated drinks trade, but current Suntory president and chairman Nobutada Saji, grandson of the firm's founder, will retain a guiding role as chairman with representative rights, the sources added. While other family members serve as executives at Suntory businesses, Saji, 68, had previously said his successor wouldn't necessarily be an insider.

After 12 years running Japan's second-biggest convenience store chain, the 55-year-old, fluent English-speaking Niinami brings experience of managing international operations, answering shareholder concerns, and a thick contacts book that includes Prime Minister Shinzo Abe and the successful Tokyo 2020 Olympic bid committee.

In a year of major changes at the company that introduced single malt whisky to Japan in the 1920s, Suntory's 1.6 trillion yen ($15.7 billion) purchase of U.S. drinks company Beam was the third-biggest overseas acquisition ever by a Japanese company.

The deal was a statement of new ambition at one of Japan's oldest companies. It's intent on growth in overseas markets to offset the impact of declining domestic demand as Japan's population falls. To do that it's prepared to do battle for assets with the likes of drinks industry leader Diageo PLC , home of Captain Morgan rum and Johnnie Walker whisky, and number two Pernod Ricard SA, owner of Absolut vodka and Martell brandy.

Before the Beam deal, more than 90 percent of Suntory's business - 2013 revenue was 2.04 trillion yen ($20 billion) - was in Japan. The acquisition deal brought Jim Beam and Maker's Mark bourbons, Courvoisier cognac and Sauza tequila into the Suntory group, along with products like Bowmore Scotch and Japanese whisky Yamazaki.