In an annual filing with the U.S. Securities and Exchange Commission, the Wall Street bank said regulators are looking into its "allocations of and trading in fixed-income securities" as well as its financial advisory services.

In the prior quarter, its long list of regulatory investigations, reviews and litigation into matters ranging from the municipal-bond market to insider trading did not include those terms.

Goldman also lowered its estimate of legal losses it may face beyond what it has set aside to $3.6 billion (2.1 billion pounds) from a previous estimate of $4 billion.

(Reporting by Lauren Tara LaCapra; Editing by David Gregorio)