Goldman Sachs Group posted a wider-than-expected loss of $428 million for the third quarter, only its second quarterly loss as a public company, hurt by sharp declines in the value of investment securities and customer trading assets. Chief Executive Lloyd Blankfein cited difficult market conditions and a lack of confidence among investors and corporate clients for the poor results. \"Our results were significantly impacted by the environment and we were disappointed to record a loss in the quarter,\" Blankfein said. Shares of the largest US investment bank by assets were down 2 per cent in premarket trading.