Goldman Sachs Group Inc (GS) will likely record a loss in the third quarter, only the second quarterly loss in the Wall Street titan's history, hurt by weakness across trading and investment banking, equity market declines and wider credit spreads during the period, Citigroup said.

The latest cut to Goldman's outlook by Citigroup analyst Horowitz -- a five-star rated analyst according to StarMine for the accuracy of his earnings estimates on Goldman -- adds to the already grim outlook that Wall Street analysts have for U.S. banks' third-quarter results.

Analysts are estimating that financial companies in the Standard & Poor's 500 index will report earnings only 3.9% higher than a year earlier, instead of the 14.6% increase they forecast on August 1, according to Thomson Reuters Proprietary Research.

The first big bank to post results will be JPMorgan Chase & Co (NYSE: JPM) on October 13. Goldman will report its third-quarter results on October 18.