France's second-biggest listed bank Societe Generale
The bank, which like larger French rival BNP Paribas
The toxic asset portfolio, which includes mortgage-backed securities, stood at 18.6 billion euros at the end of October, the bank said.
We are giving priority to the strengthening of the group's capital, SocGen Chief Executive Frederic Oudea said in a statement, adding that there would be a significant fall in bonuses at its corporate and investment bank.
Third-quarter profit fell to 622 million euros from 896 million in the same period a year earlier. This was worse than consensus forecasts for profit of 858 million, according to a Reuters poll.
The bank wrote down the value of its Greek debt holdings by 60 percent, in line with what its larger French rival BNP has done. In addition, Societe Generale wrote down the value of some consumer-credit activities by 200 million euros.
SocGen, alongside European banks, is reducing its exposure to eurozone sovereign debt. Between September and October the bank's holdings of peripheral euro area debt fell to 3.43 billion euros, from 3.65 billion. However, holdings of Italian debt rose slightly, to 1.57 billion euros, from 1.55 billion.
($1 = 0.727 Euros)
(Reporting by Lionel Laurent, editing by Leila Abboud)