ABU DHABI, April 20 (Reuters) - Mubadala Capital, an arm of Abu Dhabi's state fund Mubadala, said it had conudcted a private equity transaction with European fund manager Ardian, which had committed to invest $2.5 billion in the deal.

It is the first time that Mubadala Capital is accepting capital from third-party investors, Mubadala said in a statement on Thursday.

The deal has two components: Ardian is acquiring an interest in a private equity portfolio currently managed by Mubadala Capital, and Mubadala is establishing a new private equity fund in which Ardian will be a lead investor.

(Reporting by Stanley Carvalho; Writing by Saeed Azhar; Editing by Andrew Torchia) ((Saeed.Azhar@thomsonreuters.com; +65-64035664 ; Reuters Messaging: saeed.azhar.reuters.com@reuters.net))