"Our China service continued to see significant demand for its expedited ocean services, which was the primary driver of the increase in consolidated operating income year over year," said Matson CEO Matt Cox.

He said the new premium service enjoyed record volumes and continues to surpass the company's one-time biggest market of Hawaii.

Matson said the volume increase in its China-US service came primarily from its CLX+ service. Launched last May, the CLX+ service offers 11- to 16-day transits from Chinese ports straight to Long Beach.

In response to the high transpacific demand, Matson launched a third service, CCX, in July. The CCX offers 12- to 14-day transits from Chinese ports with the first US stop in Oakland before Long Beach.

The company said the total number of eastbound voyages from China increased by nine in the second quarter, six of which were the CLX+ service. The other three were extra loaders on Matson's long-running CLX service from China, which also stops in Okinawa, Guam, and Honolulu.

China container volumes grew 59 per cent from a year earlier to 43,600 FEU in the second quarter. Matson's second-largest ocean business by volume, Hawaii containers, grew 10 per cent year on year in the second quarter to 39,800 FEU.

The company attributed the gain to the resumption of tourism to the island after initial Covid lockdowns were lifted.

Matson said the transpacific continues to see high demand coupled with congestion at load ports, adding that all its premium services look to be nearly full through the first quarter of 2022.