Shares of Exxon Mobil (XOM) - Get Report were down Friday after reporting the weakest quarterly profit since 1999. The energy giant reported a quarterly profit of $0.41 a share, that's a quarter short of forecasts. Revenue fell 22 percent to $57.7 billion. The company says lower prices for oil and gas and weaker margins from its refining operations were the reason for the shortfall. Exxon is also cutting exploration spending to manage through the lower prices.