May 15 (Reuters) - Arm Holdings is facing an

antitrust probe by the U.S. Federal Trade Commission over the

British chip designer's licensing of its semiconductor

technology, part of ongoing global scrutiny of the business,

Bloomberg News reported on Friday.

The FTC is investigating whether Arm is trying to illegally

monopolize parts of the semiconductor market. It is looking to

assess if Arm will reject or downgrade the licensing agreements

for its chip blueprints used to design central processing units,

the report said, citing people familiar with the matter.

Earlier this year, the US regulator notified Arm of the

investigation and demanded the company preserve documents,

according to Bloomberg.

A big portion of Arm's revenue comes from licensing its

technology to companies such as Nvidia ( NVDA ) and Apple ( AAPL )

and collecting royalty payments on design use.

Reuters was not able to verify the report. Both Arm and the

FTC did not immediately respond to Reuters requests for comment.

Regulators outside the U.S. are also probing Arm's

practices.

South Korea's antitrust regulator was investigating the

Seoul offices of Arm in November, as part of ongoing scrutiny of

the company's licensing practices.