Goldman Sachs raised a closely watched measure of its legal costs by $500 million, the Wall Street firm's finance chief said on Wednesday.

Speaking during a conference call with fixed-income analysts, Goldman chief financial officer Harvey Schwartz said the New York firm had upped the top of the range of "reasonably possible" legal costs to $4 billion above what it has set aside in reserves. That was up from $3.5 billion at the end of June.