Goldman Sachs says its fourth-quarter profit dropped 21 percent as revenue from mortgages and trading in bonds and other securities weakened.

Goldman earned $2.25 billion in the October-December quarter after paying dividends on preferred shares, down from $2.83 billion in the same period a year earlier.

That worked out to $4.60 per share, down from $5.60 per share a year earlier. The results were well above the earnings of $4.18 per share that analysts were expecting.

Revenue slipped 5 percent to $8.78 billion, but exceeded analysts' forecast of $7.72 billion. Recent weakness in trading of bonds, currencies and commodities have depressed earnings at Goldman.

Goldman's CEO Lloyd Blankfein said in a prepared statement that the company has worked to keep costs down "to provide solid returns even in a somewhat challenging environment."

The decline came despite a 22 percent jump in earnings in Goldman's investment banking business in the fourth quarter, to $1.72 billion.

The company maintained its quarterly dividend at 55 cents.

Goldman's shares slipped 25 cents, or 0.1 percent, to $179 in pre-market trading Thursday.