A slowdown in the flow of containers through the giant ports of southern China is providing an amber warning light that all is not well in the vast workshops of China's eastern seaboard.

Container traffic growth in Shenzhen and Shanghai, China's biggest ports, slowed in June as weakening demand took its toll on trans-Pacific trade. Traffic at Shenzhen, the world's fourth-largest port, fell in June by 0.6 per cent from the previous month and grew only 3.5 per cent against the same month last year. Throughput in the first half of the year was up 7 per cent, half the rate of growth last year.

The slump in traffic to the West Coast of the United States is hitting the massive Yantian container terminal operated by Hutchison Whampoa. It is suffering volume declines for the first time. A majority of Yantian's traffic is from shipping lines servicing routes to North America, where demand has been driven down by the American property slump and dwindling consumption of household consumer goods. It is expected to report a drop in volumes for the first half, having declined for five consecutive months.

Shanghai's container throughput is slowing, too. Growth in the first half of the year slowed to 10.4 per cent, half last year's rate of increase, and analysts are predicting hard times ahead. “We've seen the peak. Container terminal shipments are now in a downtrend,” Geoffrey Cheng, an analyst for the Daiwa Institute of Research, said. “It's unusual that throughput in June, the peak season for container shipping, would slow from May.”

Shipping lines provide further evidence that the American and European slowdown is hurting Chinese exporters. Maersk, the Danish shipping group that acquired P&O Nedlloyd in 2005, reduced its capacity on Asian routes last year and gave warning in its half-year report in May that volumes on its Far East-to-North America routes were down 18 per cent. The company has refrained from providing its usual guidance to investors on the outlook for the year. “In general on Asia to Europe, we are seeing a slowdown. There are real uncertainties as to how growth will develop,” a Maersk spokesman said.

The Chinese economy is still growing - according to official statistics, the People's Republic generated 10.1 per cent more value in goods and services in the second quarter - but the rate is down from the increase of 11.9 per cent for the whole of 2007. Inflation is surging, at 7.9 per cent in the first half of 2008, and food prices, a bigger portion of household budgets than in Britain, rose by 20 per cent.

Inflationary pressures, a stronger currency and soaring costs are eroding the competitiveness of the workshops on the Pearl River Delta. Some are calling for the return of the tax rebates that drove Chinese exports in the 1990s. In a world of expensive fuel, China's distance from the markets of the West is becoming a challenge.

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