U.S. trade regulator to investigate whether iPhones are infringing chipmaker’s patents.

Qualcomm on Wednesday welcomed the U.S. International Trade Commission (ITC)’s decision to investigate the chip maker’s patent complaint against Apple.

The regulator will look into whether the import and sale of various Apple products, including the iPhone 7, infringe certain Qualcomm patents. It will set a target date for concluding its investigation within 45 days of commencing it. Any remedial orders will be effective immediately and become final 60 days after issuance.

"Qualcomm is pleased with the ITC’s decision to investigate Apple’s unfair trade practices and the unauthorised importation of products using Qualcomm’s patents," said Don Rosenberg, Qualcomm EVP and general counsel, in a statement. "We look forward to the ITC’s expeditious investigation of Apple’s ongoing infringement of our intellectual property and the accelerated relief that the Commission can provide."

Qualcomm petitioned the ITC in July to issue a Limited Exclusion Order (LEO) banning the sale of Apple products that allegedly infringe its patents. At the same time, it also filed a patent-infringement suit with the U.S. District Court for the Southern District of California.

The ITC probe is the latest development in an increasingly bitter dispute between Qualcomm and Apple.

Apple filed a $1 billion lawsuit against Qualcomm in January, accusing it of various anti-competitive practices.

Qualcomm struck back with a lawsuit in April that claimed Apple had lied to regulators, breached agreements, and deliberately limited the performance of Qualcomm modem chips installed in the iPhone 7.

In May, Apple started withholding patent-royalty payments to suppliers using Qualcomm technology, prompting Qualcomm to sue said suppliers.