Goldman Sachs continued its strong run in the debt capital markets during the second quarter - edging out the previous quarter's record revenues for debt underwriting by $1 million - but 'more challenging' conditions for fixed income trading set alarm bells ringing.

The US bank this morning posted net profits of $1.9 billion for the three months to June 30, more than double those of same period a year ago, in a set of results that chairman and chief executive Lloyd Blankfein described as "solid" given the "mixed economic sentiment during the quarter".