Dealers say it's because of delay in index inclusion
Brent crude futures rose 52 cents, or 0.6%, to $89.84 a barrel by 1027 GMT and U.S. crude futures rose by 52 cents, or 0.6%, to $82.67
Prices also drew support from analyst expectations of possible supply cuts from the Organization of the Petroleum Exporting Countries and allies (OPEC+)
In a step that may increase prices in India, the group has decided to reduce output quotas for October, after a fall in global oil demand outlook.
Russia, the world's second-largest oil producer and a key OPEC+ member, does not support a production cut at this time and the producer group is likely to decide to keep output steady
IEA members nations could release more oil from strategic petroleum reserves (SPR) if they find it necessary when the current scheme expires, the head of the agency also said
Oil prices were mixed on Monday as investors balanced expectations the OPEC will cut output to support prices against concerns sparked by Federal Reserve Chairman Jerome Powell
Oil has soared in 2022, coming close in March to an all-time high of $147 after Russia's invasion of Ukraine exacerbated supply concerns
Brent crude futures rose 32 cents to $96.80 a barrel by 0004 GMT, after a choppy session on Monday when they dropped by more than $4 before paring losses to trade near flat
Oil prices have fallen over recession feads and OPEC output, driving investors into frenzy
The 23-member OPEC+ alliance, which includes Russia, is struggling to produce enough oil to keep up with the rebounding demand for fuel since the Covid-19 pandemic
US crude notched a sixth weekly gain on tight U.S. supply, which has prompted talk of fuel export curbs or a windfall tax on oil and gas producers.
Oil prices were roughly unchanged on Friday, clinging to gains made in the previous session
"Investors scooped up profit after a sharp gain last Friday," said Naohiro Niimura, a partner at Market Risk Advisory.
Analysts expect the group, known as OPEC+, to stay on its schedule of gradual increases to restore production cuts made during the depths of the coronavirus pandemic in 2020
Saudi Arabia and UAE, which are among just a handful of producers with spare capacity, have snubbed Western calls for more crude.
It will also evaluate the Russian offer to sell crude oil at discounted prices after considering aspects such as insurance and freight required to move the fuel from the non-traditional supplier
The OPEC+ coalition of oil producers led by Saudi Arabia and non-cartel members led by Russia are weighing whether to increase oil production by 400,000 barrels per day in April
A source told Reuters that OPEC+ agreed to increase oil production by 400,000 bpd from March after a short meeting
Brent crude futures gained 1 cent to $78.99 a barrel at 0239 GMT, while U.S. West Texas Intermediate (WTI) crude futures slipped 2 cents to $76.06 a barrel.