ZURICH, Jan 19 Reuters Swiss engineering group ABB39;s operations in China are being scrutinised by two U.S. Congress committees dedicated to investigating security threats and risks posed by Beijing, documents showed on Friday.

The committees from the House of Representatives sent a letter this week to ABB inviting executives to public hearings to clarify the company39;s relationship with a Chinese stateowned company that they said raised significant concerns.

Although ABB had provided documents to answer requests last year, many important questions remained unanswered, the letter said, and it had not responded in good faith.

ABB shares fell 3 on Friday morning after Sweden39;s Sverige Radio reported on the investigations by the Committee of Homeland Security and the Select Committee on the Strategic Competition between the U.S. and the Chinese Communist Party.

ABB said on Friday it sold its control and electrification equipment to many crane manufacturers, including Chinese companies, which in turn sold the cranes directly to U.S. ports.

Still, the Swiss company said it was taking the committee39;s request for further information seriously.

The letter sent to ABB Chief Executive Bjorn Rosengren raised concerns about the installation of ABB equipment by Shanghai Zhenhua Heavy Industries ZPMC, a stateowned Chinese company, onto U.S.bound shiptoshore cranes.

The committees wanted to probe potential cybersecurity risks, foreign intelligence threats, and supply chain…