May 15 (Reuters) - Bill Ackman's hedge fund Pershing Square will disclose a new position in Microsoft ( MSFT ) later in the day, the billionaire investor said on Friday, arguing that the tech giant sits at a "highly compelling valuation".

Ackman's new closed-end fund Pershing Square USA, which debuted on the NYSE last month, has also recently made Microsoft ( MSFT ) a core holding, he said in a post on social media platform X.

Pershing's bet on Microsoft ( MSFT ) comes amid Ackman's growing appetite for tech holdings. In February, he said Pershing had bought shares in Meta Platforms, betting the Facebook parent will benefit from artificial intelligence.

Last year, he made a new investment in Amazon and the firm previously invested in Alphabet in late 2022.

Microsoft ( MSFT ) shares have fallen more than 15% so far this year, as investors worry that the company's early-mover advantage in the AI race is losing ground as Google and Amazon make strong progress in their own AI efforts.

(Reporting by Deborah Sophia in Bengaluru; Editing by Arun Koyyur)