* Vivendi to sell 27.3 pct stake for 2 bln euros
* China's Tencent, Ontario pension fund taking stakes
* Ubisoft makes Assassin's Creed, South Park games (Adds details of Tencent investment, bullets)
PARIS/BEIJING, March 21 (Reuters) - French media giant Vivendi is selling its stake in Ubisoft for 2 billion euros ($2.45 billion) to investors including Chinese tech titan Tencent, ending a potential takeover battle for the French video games maker.
Billionaire Vincent Bollore's Vivendi, which had been raising its holding in Ubisoft, has agreed to sell its 27.3 percent stake in the company, best known for its Assassin's Creed and South Park games.
Tencent Holdings Ltd, which dominates China's mobile gaming market, is investing almost 370 million euros for a 5 percent stake, while the Ontario Teachers' Pension Plan is spending 250 million euros for a 3.4 percent stake.
Ubisoft and Tencent will also form a strategic partnership to boost Ubisoft's reach into China, the world's largest video game market with estimated sales of $32.5 billion last year, according to data from gaming consultancy Newzoo.
The move represents a strategic setback for Bollore and Vivendi, which has pledged to make video gaming one of its key pillars along with advertising, music and pay-TV. As part of the deal Vivendi has committed to not acquire any further shares in Ubisoft for five years.
Vivendi's stake-building since 2015 had prompted Ubisoft's founding Guillemot family to court Canadian investors to fend off any hostile takeover.
After the sale Vivendi will remain active in video gaming through its acquisition of mobile game maker Gameloft, which was also founded by a Guillemot brother but is much smaller than Ubisoft, the French leader in this market.
Along with the investments from Tencent and Ontario Teachers, the deal also includes a share buy-back by Ubisoft that adds up to an 8.1 percent stake, as well as a share purchase by Guillemot Brothers SE and an accelerated book building with institutional investors.
Ubisoft said Vivendi had approached it several weeks ago about its intention eventually to sell its stake. Ubisoft started tapping up potential investors at that stage.
Tencent, Asia's biggest listed firm with a market value of around $540 billion, is investing heavily to expand its gaming empire at home and abroad. It launched some of its top games overseas last year, and last month invested 3 billion yuan ($474.73 million) in Chinese peer Shanda Games.
The firm, which stretches from social media to online payment, announced a strong fourth quarter profit on Wednesday, but said mobile gaming revenue growth had slowed. ($1 = 0.8093 euros) ($1 = 6.3194 Chinese yuan renminbi) (Reporting by Maya Nikolaeva and Matthieu Rosemain in Paris and Cate Cadell in Beijing Writing by Adam Jourdan Editing by David Goodman and Muralikumar Anantharaman)