Tokyo - Crude prices dipped in Asian trade on Tuesday on easing supply concerns as a landmark deal to curb oil-rich Iran's disputed nuclear programme came into force.

The US benchmark contract, West Texas Intermediate for delivery in February, was down 48 cents to $93.89 a barrel in mid-morning Asian trade and Brent crude for March eased five cents to $106.30.

Iran on Monday halted production of 20 percent enriched uranium, as an interim deal between Tehran and world powers first reached in November came into force.

Under the agreement, Iran agreed to curb parts of its nuclear drive for six months in exchange for receiving modest relief from international sanctions and a promise by the so-called P5+1 - Britain, China, France, Russia, the United States plus Germany - not to impose new sanctions against its hard-hit economy.

The deal helps reduce geopolitical risks in the oil-producing Middle East region, reducing threats of supply disruptions.

“It definitely helped in terms of easing prices further,” said Desmond Chua, market analyst at CMC Markets in Singapore.

Flat Chinese economic growth also weighed on the market because of its impact on oil demand.

China's GDP registered flat growth of 7.7 percent last year, maintaining its slowest expansion in more than a decade.

Kelly Teoh, market strategist at IG Markets in Singapore, said investors were closely watching growth in the world's second biggest economy.

“Everyone is trying to get a gauge about what's going to happen,” Teoh told reporters. - AFP