ABU DHABI, March 5 (Reuters) - Abu Dhabi investment fund Mubadala Development Co MUDEV.UL sold nearly a third of its stake in Advanced Micro Devices AMD.O , booking a tiny gain on its investments in the micro chip maker.

Mubadala sold 45 million shares in AMD for around $613 million while retaining 97 million shares in the company.

Mubadala paid $608 million in November 2007 when it bought the shares, according to the company's statement at the time.

"In line with our strategy as a long-term investor, from time to time we will monetise assets that have significantly increased in value," Mubadala spokesman Brian Lott told Reuters on Sunday.

Mubadala, which has stakes in General Electric GE.N and private equity firm Carlyle, among others, was formally merged with another Abu Dhabi investment fund, International Petroleum Investment Co (IPIC) in January. urn:newsml:reuters.com:*:nL5N1FBOK2 .

The merger of the two created a firm with assets totalling about $125 billion based on valuations at the end of 2015.

(Reporting by Stanley Carvalho; Editing by Jacqueline Wong) ((stanley.carvalho@thomsonreuters.com; + 9712 6444431; Reuters Messaging: stanley.carvalho.thomsonreuters.com@reuters.net))