China’s market regulatory authority announced on Friday that it has opened an investigation into the US semiconductor manufacturer Qualcomm.

The authority suspects Qualcomm of violating China’s antitrust laws.

The investigation concerns Qualcomm’s acquisition of Autotalks, which the US company announced in June, according to multiple agencies.

The Chinese market regulator will examine whether Qualcomm’s acquisition of Autotalks breaches China’s antitrust law.

Qualcomm’s shares dropped 4% in pre-market trading in New York following the announcement of the investigation.