The U.S. Federal Trade Commission is seeking more details about SoftBank Group Corp's (9984.T), opens new tab planned $6.5 billion purchase of semiconductor designer Ampere Computing, Bloomberg News reported on Tuesday.

The inquiry, known formally as a second request for information, suggests the acquisition may undergo an extended government review, the report said.

SoftBank announced the purchase of the startup in March, part of its efforts to ramp up its investments in artificial intelligence infrastructure.

The report did not state the reasoning for the FTC request.

SoftBank, Ampere and the FTC did not immediately respond to a request for comment.

SoftBank is an active investor in U.S. tech. It is leading the financing for the $500 billion Stargate data centre project and has agreed to invest $32 billion in ChatGPT-maker OpenAI.

Reporting by Devika Nair in Bengaluru and Anton Bridge in Tokyo; Editing by Sherry Jacob-Phillips and Edwina Gibbs