Societe Generale today missed third-quarter income forecasts and raised reserves for litigation costs by €300m, knocking the French bank's shares.
Investors are concerned that pending legal disputes, for which SocGen has set aside €2.2 billion, could hurt its dividend payouts.
The bank said it should resolve two legal disputes with US authorities within the coming months.
The French bank reported a 15% fall in third-quarter net income to €932m, below analysts' estimates of €1 billion, according to a Reuters poll.
Like other European banks, the quarterly result was weighed down by a slump in fixed income and equities trading.
The bank said it was in talks with US authorities over two investigations, the first concerning the Libyan Investment Authority (LIA) and the other over interest rate benchmarks.
In May, SocGen reached an 11th-hour settlement over LIA allegations that trades were secured as part of a "fraudulent and corrupt scheme" involving the payment of $58.5m by SocGen to a Panamanian-registered company.
But the two disputes may not mark the end of SocGen's legal problems, with the bank still in talks with US authorities over dollar transfers it made on behalf of entities based in countries subject to economic sanctions.
Profits are being squeezed by revenue pressure in French retail banking, due to low interest rates, investments in digital technologies and a slump in trading.
Revenue at SocGen's investment banking arm slumped 15%, mirroring results at other banks including French rival BNP Paribas.
SocGen's fixed income trading revenue fell 27.8%, which compared with a 26% drop at BNP Paribas and more than 30% fall at others, such as Deutsche Bank.
The bank also underperformed rivals in equities and prime services trading, which fell 19.3%.
