Adds details in paragraph 3,4 5,6 adds MGX response in paragraph 2

Aug 5 (Reuters) - Abu Dhabi-based MGX is considering plans to raise as much as $25 billion in third-party capital as the investment group looks to ramp up its artificial intelligence holdings, Bloomberg News reported on Tuesday, citing people familiar with the matter.

MGX declined to comment on the report and Reuters could not immediately verify it.

Company executives are weighing raising money from financial and strategic investors in Abu Dhabi and beyond, but Mubadala Investment Co and AI firm G42 will remain MGX's main backers, the report said.

No final decisions have been made, according to the report.

MGX, which has invested in OpenAI and Elon Musk's xAI, is chaired by Sheikh Tahnoon bin Zayed Al Nahyan, the UAE's national security adviser and a brother of UAE President Sheikh Mohammed bin Zayed.

The Financial Times reported last week that French AI startup Mistral is in talks with MGX and other investors to raise $1 billion at a valuation of $10 billion.

(Reporting by Dheeraj Kumar in Bengaluru; Editing by Mrigank Dhaniwala and Devika Syamnath)

((Dheeraj.Kumar@thomsonreuters.com;))