Sharecast - At 0820 BST, the FTSE 100 was up 0.6% at 7,676.69.
Over the weekend, OPEC+ unexpectedly announced it would cut output by 1.1m barrels a day from next month, sending oil prices surging. Brent crude rose 5.6% to $84.12 a barrel, while West Texas Intermediate was 5.3% firmer at $79.69.
Richard Hunter, head of markets at Interactive Investor, said: "Markets in the UK opened the new quarter on the front foot, with the spike in the oil price boosting the shares of BP (LON:BP) and Shell (LON:RDSa), in turn adding several points to the FTSE 100 given the size of the index’s exposure to the oil and gas sector.
"Indeed, there was a more general feel of a measured return to a risk-on approach, with some strength also seen in the miners and the more recently beleaguered banking stocks. The index as a whole is currently up by 3% in the year to date, albeit off first quarter highs, and is trying to re-establish the strength of its recent performance.
"Its exposure to stable, cash generative and to some extent inflation-proof sectors, coupled with a sprinkling of defensive stocks and an average overall dividend yield of 3.7% ticks many boxes for the more cautious investor, including those from overseas who also appreciate the global exposure which the index provides."
Investors were also digesting the latest data out of China, which showed that manufacturing activity unexpectedly eased in March.
The Caixin purchasing managers index for the sector, which covers smaller and export-oriented businesses, fell to 50.0 - the level that separates contraction from expansion - from 51.6 in February. Economists were expecting a reading of 51.4.
Both output and new orders rose at softer paces while foreign sales and employment fell. Meanwhile, buying activity rose modestly for the second month.
Pantheon Macroeconomics said: "Today’s set of PMIs point to a risk of China’s recovery losing momentum, while dismal global demand weighs on growth in north-east Asia."
In equity markets, BP and Shell were the standout gainers on the FTSE 100 index, up 4.4% and 3.8%, respectively.
On the FTSE 250, Tullow Oil (LON:TLW), Energean, Hunting (LON:HTG) and Wood Group also gained.
Elsewhere, NatWest (LON:NWG) was in focus after the UK government said it has extended plans to sell down its stake in the bank.
UK Government Investments (UKGI), which manages the government’s 41.5% shareholding in the lender, first announced plans to start slowing selling down its stake in July 2021. It was extended last summer until 11 August 2023, and it will now be extended once again, to 11 August 2025.
Cineworld tumbled more than 30% as it said it had ended the sale process for its US, UK and Ireland businesses after failing to find an all-cash buyer. The company also said it has reached a conditional deal with lenders to exit bankruptcy and announced plans to raise $2.26bn (£1.8bn) in new funding.
Market Movers
FTSE 100 (UKX) 7,676.69 0.59%
FTSE 250 (MCX) 18,942.00 0.07%
techMARK (TASX) 4,516.19 -0.27%
FTSE 100 - Risers
BP (BP.) 533.00p 4.35%
Shell (SHEL) 2,397.00p 3.83%
SEGRO (SGRO) 778.00p 1.35%
Ocado Group (LON:OCDO) 542.00p 1.31%
Imperial Brands (LON:IMB) 1,888.00p 1.29%
Land Securities Group (LAND (LON:LAND)) 628.40p 1.16%
Frasers Group (FRAS) 785.50p 1.09%
Anglo American (LON:AAL) 2,707.00p 1.08%
HSBC Holdings (LON:HSBA) 554.70p 0.91%
Centrica (LON:CNA) 107.00p 0.90%
FTSE 100 - Fallers
Endeavour Mining (EDV (LON:EDV)) 1,950.00p -2.40%
International Consolidated Airlines Group (LON:ICAG) SA (CDI) (IAG) 147.80p -2.11%
Burberry Group (LON:BRBY) 2,559.00p -1.04%
Entain (LON:ENT) 1,244.00p -0.99%
Flutter Entertainment (CDI) (FLTR) 14,495.00p -0.92%
Hiscox Limited (DI) (LON:HSX) 1,100.00p -0.81%
3i Group (LON:III) 1,672.50p -0.74%
Ashtead Group (LON:AHT) 4,923.00p -0.71%
Auto Trader Group (AUTO) 612.00p -0.68%
Rentokil Initial (LON:RTO) 587.60p -0.68%
FTSE 250 - Risers
Tullow Oil (TLW) 33.32p 5.64%
Aston Martin Lagonda Global Holdings (AML) 238.20p 4.34%
Energean (ENOG) 1,350.00p 3.69%
Hunting (HTG) 244.00p 3.39%
Just Group (JUST) 88.40p 2.97%
Ithaca Energy (ITH) 153.60p 2.74%
Wood Group (John) (WG.) 205.00p 2.50%
Mitchells & Butlers (MAB) 168.50p 2.43%
TI Fluid Systems (TIFS) 110.00p 2.42%
Diversified Energy Company (DEC) 96.80p 2.33%
FTSE 250 - Fallers
Bridgepoint Group (Reg S) (BPT) 210.60p -4.62%
Man Group (EMG) 227.30p -3.44%
Wizz Air Holdings (LON:WIZZ) 2,882.00p -3.06%
easyJet (LON:EZJ) 506.00p -2.39%
OSB Group (OSB) 470.80p -2.24%
Wetherspoon (J.D.) (JDW) 699.50p -2.17%
Centamin (DI) (LON:CEY) 102.00p -2.16%
QinetiQ Group (QQ.) 318.40p -1.97%
Domino's Pizza Group (DOM) 282.00p -1.61%
Molten Ventures (GROW) 269.60p -1.46%