Sept 3 (Reuters) - The U.S. Department of Justice has

sent a subpoena to Nvidia ( NVDA ) as it deepens its probe into

the AI heavyweight's antitrust practices, Bloomberg News

reported on Tuesday, citing people familiar with the

investigation.

The antitrust watchdog had previously delivered

questionnaires, and has now sent legally binding requests to

Nvidia ( NVDA ), the report said, adding that other companies had also

received subpoenas.

Officials are concerned that the chipmaker is making it

harder to switch to other suppliers and penalizes buyers that do

not exclusively use its artificial intelligence chips, the

report said.

Last month, the Information reported that the Department of

Justice had launched an investigation into Nvidia ( NVDA ) after

complaints from competitors that it had abused its market

dominance.

The subpoena comes at a delicate time for AI-related

companies as investors recalibrate expectations around the

technology amid worries about slow payoffs from hefty

investments in it.

Nvidia's ( NVDA ) quarterly forecast, which fell short of investors'

expectations last week, has also softened the optimism around

AI.

The company's shares fell 2.5% in extended trading on

Tuesday after losing 9.5% in the regular session, slashing

Nvidia's ( NVDA ) market capitalization by $279 billion, a record one-day

loss for any company.

The shares, however, are still up 141% so far this year,

thanks to a dizzying rally sparked by AI expectations.

Nvidia ( NVDA ) and the DoJ declined to respond to Reuters requests

for comment.

(Reporting by Niket Nishant in Bengaluru; Additional reporting

by Jody Godoy and Max Cherney; Editing by Tasim Zahid and

Shinjini Ganguli)