PARIS, Aug 31 (Reuters) - Billionaire hedge fund manager William Ackman’s Pershing Square fund has committed to acquire an additional 2.9% of Universal Music Group (UMG) for $1.149 billion, French conglomerate Vivendi said on Tuesday. Vivendi said the transaction is based on an enterprise value of 35 billion euros ($41.40 billion) for 100% of UMG’s share capital. Vivendi said that following its sale of a 7.1% UMG stake to Pershing Square in August, the fund will now own 10% of UMG’s share capital. The closing related to the additional 2.9% stake will take place by Sept. 9. ($1 = 0.8455 euros) (Reporting by GV De Clercq, Editing by Louise Heavens) Our Standards: The Thomson Reuters Trust Principles.