Transtech Optelecom Science (HKG:9963) said it has entered into a framework purchase agreement to buy optical fibre preforms from Yinhu Optical Fiber (Tianjin), according to a Jan. 16 Hong Kong bourse filing.

Shares of the optical fiber manufacturer were down nearly 10% in Monday's late morning trade.

Under the agreement, Transtech's wholly owned unit will purchase optical fibre preforms through to the end of 2026, subject to an annual cap of HK$9.8 million.

Yinhu Optical Fiber is more than 30% owned by Futong Group, one of Transtech's controlling shareholders, the company said.