The SEC is examining whether banks favor big investors, leaving smaller ones at a disadvantage, the newspaper said, citing unidentified people familiar with the matter.

The regulator has made requests about several deals, including Verizon Communications Inc's $49 billion bond offering last year, the Journal said.

Representatives of the banks declined to comment. SEC officials did not immediately respond to requests for comment.

News of the SEC probe followed a disclosure by Goldman Sachs on Friday morning that a regulator was looking into its "allocations of and trading in fixed-income securities," as well as its financial advisory services.

In the prior quarter, the bank's 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 from a previous estimate of $4 billion.

(Reporting by Lauren Tara LaCapra in New York; Additional reporting by Sarah N. Lynch in Washington; Editing by David Gregorio and Jonathan Oatis)