DUBAI - The OPEC+ Joint Technical Committee (JTC) expects a 2023 oil market deficit of 300,000 barrels per day (bpd) under its base case, according to a document seen by Reuters on Thursday.

The JTC, which met on Wednesday, expects demand to lag supply by 400,000 bpd this year, a downward revision of 500,000 bpd after new production assumptions were taken into account.

It also forecast a widening of the deficit to 1.8 million bpd in the fourth quarter of 2023, the document showed.

The JTC assessment took into consideration lower production by its members for the rest of 2022 and for 2023.

"None of the member countries are expected to produce at higher levels than they did in July, except for Saudi Arabia, UAE and Kuwait," an OPEC source said.

"The figures have taken that into account."

The JTC advises the Organization of the Petroleum Exporting Countries (OPEC) and allies including Russia, a group collectively known as OPEC+, on market fundamentals.

Many OPEC and OPEC+ producers are lacking the capacity to raise output because of insufficient oilfield investment and Western sanctions against Iran, Venezuela and Russia. Output from countries that are part of the deal was almost 3 million bpd below quota in July.

The committee said the market would be tight for the remainder of the year and for 2023, adding that preliminary data shows that OECD commercial oil stocks will remain below the five-year average for the remainder of 2022 and for 2023.

(Reporting by Maha El Dahan and Ahmad Ghaddar; writing by Nadine Awadalla; editing by Jason Neely and David Goodman)