Feb 23 (Reuters) - Goldman Sachs GS.N raised its Brent and West Texas Intermediate crude forecasts for the fourth quarter of 2026 by $6 to $60 and $56 respectively, citing lower-than-expected OECD stocks, even as it continues to assume no Iran-related supply disruption and maintains its view of a 2026 surplus.

In a note dated Sunday, the bank said it expects OPEC+ to begin gradually increasing production in the second quarter of 2026, given that OECD inventories have not built.

The bank maintained its 2026 surplus forecast of 2.3 million barrels per day (bpd), assuming no major supply disruption and no Russia-Ukraine peace.

The bank said its 2026 surplus reflects offsetting 0.2 million bpd downgrades to supply and demand on slightly softer growth in Asia.

Goldman, however, expects downside risks of $5 for Brent and $8 for WTI for the fourth quarter of 2026 if potential sanctions relief for Iran or Russia accelerates landed stock builds and unlocks higher supply in the longer term.

It expects Brent and WTI to average $65 and $61, respectively, in 2027 and to rise to $70 and $66 by December 2027 on the back of solid demand and slowing supply growth.

(Reporting by Pablo Sinha in Bengaluru; Editing by Thomas Derpinghaus)

((Pablo.Sinha@thomsonreuters.com;))