The 24-hour strike is blocking six ships from entering Fos-Lavera near Marseille, including two oil tankers, the port authority said.

It also prevented three tankers from entering the Nantes Saint-Nazaire port.

US crude rose $1.24 to $102.46 a barrel by 1210 GMT, extending the 36-cent gain on Tuesday.

London Brent added $1.01 to $101.61.

'The immediate trend still looks lower but we're having a bit of a rebound,' said Tony Machacek, an oil broker at Bache Commodities Ltd.

'The French strike is supporting gas oil.'

Gas oil, the benchmark for diesel and heating oil in Europe, gained more than crude. It was up 1.4 per cent at $921.75 a tonne.

French port and dock workers started the strike at 0500 GMT at French state-owned ports to protest against government plans to privatise the loading activities of seven out of nine of the public ports.

A renewed bout of weakness in the dollar also supported oil and some commodities. Gold, which like crude oil is used by investors as a hedge against inflation, hit a one-week high.

'The dollar's fall has prompted buying but traders are reluctant to take large positions ahead of the end of the quarter,' said Shuji Sugata, a manager at Mitsubishi Corp Futures and Securities Ltd in Tokyo.

Oil's gain on Tuesday snapped a losing streak in which prices tumbled from an all-time high of $111.80 on March 17.

Analysts said a workers' strike in Gabon that had halted 60,000 barrels of daily output from a Shell subsidiary in the West African nation also encouraged oil's gains.

There was also a possibility that Iraq's oil output could be affected by violence in the country's south.

Oil production and exports from the southern oilfields could be disrupted in three days if workers cannot reach their offices due to fighting in Basra, a Southern Oil Company official said.

The market is now shifting its focus to the US government's weekly report on crude oil inventories to be released at 1430 GMT.

Oil analysts polled by Reuters expect this week's government data to show a third consecutive increase in weekly US crude oil stocks, up 1.7 million barrels.

Gasoline stocks were forecast to show a decline of 800,000 barrels, while distillates were expected to fall 1.7 million barrels. -- REUTERS