Taiwan's Yang Ming has signed a deal to charter four more boxships from Japanese owner Shoei Kisen.

The 11,000-teu vessels will be delivered in the first three quarters of 2022.

"In order to enhance the company’s mid- to long-term operational efficiency and competitiveness, Yang Ming continues its fleet optimisation plan during recent years," it said.

Yang Ming had already agreed to take 10 sisterships from Shoei and Greece's Costamare.