SHANGHAI -- China's index of export container transport edged down in the past week ending Friday, according to the Shanghai Shipping Exchange.

The average China Containerized Freight Index (CCFI) went down 1.9 percent to 3,301.1, said the exchange.

The sub-reading for the Persian Gulf/Red Sea service led the decline with a week-on-week drop of 4.9 percent, followed by that for the west coast America service and Southeast Asia service, which both went down 3.8 percent from the previous week.

Bucking the trend, the sub-reading for the Korea service reported a week-on-week gain of 5.5 percent.

The CCFI tracks spot and contractual freight rates from Chinese container ports for 12 shipping routes across the globe, based on data from 22 international carriers.

The index was set at 1,000 on Jan 1, 1998.