TOKYO: Oil prices slid more than 1% on Tuesday, extending losses that began last week, as expectations that OPEC would agree to raise oil supply in a meeting this week added to pressure and worries over slowing demand in China dampened sentiment.

Brent crude dropped 70 cents, or 1.1%, to $62.99 a barrel by 0457 GMT, after losing 1.1% the previous day. US West Texas Intermediate (WTI) crude fell 71 cents, or 1.2%, to $59.93 a barrel, having lost 1.4% on Monday.

They both touched the lowest in more than one week.

Expectations that the Organization of the Petroleum Exporting Countries and its allies, a group known as OPEC+, would boost oil output from April are pushing prices lower, said Satoru Yoshida, a commodity analyst with Rakuten Securities.

"Concerns over an increase in OPEC+ supply and an end of Saudi Arabia's voluntary cut of 1 million barrels per day (bpd) this month weighed on oil prices," he said.

The group meets on Thursday and could discuss allowing as much as 1.5 million barrels per day (bpd) of crude back into the market.

OPEC oil output fell in February as a voluntary cut by Saudi Arabia added to reductions agreed to under the previous OPEC+ pact, a Reuters survey found, ending a run of seven consecutive monthly increases.

OPEC+ is monitoring global inventories and the rate of drawdowns will be a factor discussed on Thursday.

"Oil prices may stay under pressure as investors are making position adjustments ahead of the OPEC meeting," said Hiroyuki Kikukawa, general manager of research at Nissan Securities.

Market sentiment was also dampened by weak manufacturing data out of China, Kikukawa said.

China's factory activity growth slipped to a nine-month low in February, which may curtail Chinese crude demand and pressure oil prices.