On Tuesday, Brent crude futures slipped towards $122 as a steeper-than-expected fall in China's overall imports in March increased concerns about oil demand growth in the second biggest consumer of the world.

Front-month Brent crude slipped 30 cents to $122.37 a barrel by 00:21 a.m. Eastern Time, after settling 76 cents lower. On Monday, the contract slipped as low as $121.02, the lowest since March 15. U.S. oil was unchanged at $102.46.

From Reuters.com:

China is expected to report first-quarter growth of 8.3 percent on the year, according to a Reuters poll. That would compare with growth of 8.9 percent in the last quarter of 2011 and be the slowest in nearly three years, but still comfortably above China's target of 7.5 percent growth this year.

Oil futures are also under pressure on expectations of a further increase in U.S. commercial crude inventories, building on the biggest two-week increase in more than a decade, as higher imports easily outpaced sluggish refinery demand. Industry group American Petroleum Institute (API) is due to release its numbers later in the day.

"There have been some doubts about global oil demand growth creeping in to the market, and China's crude oil import numbers won't help change that perception very much," said Ric Spooner, chief market analyst at CMC Markets. "They are broadly in line with expectations."