Most stock markets in the Middle East ended higher on Monday, mirroring a buoyant day in oil prices and global stocks, with the Saudi index leading the gains.

Brent crude rose $3.33, or 8.4%, to $42.78 a barrel by 1216 GMT, after Pfizer said its COVID-19 vaccine was very effective and Saudi Arabia said an OPEC+ deal on output cuts could be adjusted to offset rising supply and weak demand. 

Pfizer Inc said on Monday its experimental COVID-19 vaccine was more than 90% effective, based on initial data from a large study. 

Saudi Arabia's benchmark index advanced 2.5%, its biggest intraday gain since April, led by a 2% rise in Al Rajhi Bank and a 4.4% leap in petrochemical firm Saudi Basic Industries.

The kingdom's Energy Minister Prince Abdulaziz bin Salman said the OPEC+ deal on oil output cuts could be adjusted as it has been in the past if there is consensus among members of the group. 

Dubai's main share index climbed 1.8%, led by a 6% jump in blue-chip developer Emaar Properties and a 3.1% increase in Emirates NBD Bank.

The Abu Dhabi index gained 0.8%, with the United Arab Emirates' largest lender, First Abu Dhabi Bank closing up 1.4%.

In Qatar, the index added 1.9%, as all the stocks were in positive territory except one, with petrochemical maker Industries Qatar advancing 6.8%.

The Kuwaiti index increased 1.5%, with Kuwait Finance House rising 1.8%.

The anticipated addition of Kuwait to the MSCI Emerging Market index at the end of November is expected to positively affect the flow of foreign capital in Boursa Kuwait, Kamco Invest said in a research note on Thursday.

Outside the Gulf, broad-based gains pushed Egypt's blue-chip index 1.5% higher, with financial stocks leading the pack.

(Reporting by Ateeq Shariff in Bengaluru Editing by Keith Weir) ((AteeqUr.Shariff@thomsonreuters.com; +918061822788;))