Chevron Corporation (NYSE: CVX) issued a larger-than-expected drop in second quarter earnings on Friday after net income fell 26 percent to $5.37 billion, or $2.77 per share, from $7.21 billion, or $3.66 per share, in the year ago period. Analysts polled by Reuters on average expected the second-largest U.S. oil company to report $2.96 per share.As of 10:00 am. Eastern, shares of Chevron fell 1.92 percent to $124.01in morning trade.Toyota Motor Corporation (NYSE: TM) reported first quarter profit rose to 562.1 billion yen, or $5.6 billion. The automaker also raised its full-year earnings forecast to 1.48 trillion yen ($14.8 billion), up close to 54 percent from the previous quarter.Shares of Toyota Motor rose 2.83 percent to $129.81 in early trade.Viacom, Inc. (Nasdaq: VIA) reported a 20 percent rise in net income for the fiscal third quarter. For the quarter, Viacom earned $643 million, or $1.31 per share, compared with $534 million, or $1.01 per share, in the year ago quarter.Shares of Viacom rose 6.64 percent to $79.86 in morning trade.As of 10:10 a.m. Eastern, the Dow Jones industrial average fell 37.73 points, or 0.24 percent, at 15,590.29. The S&P 500 Index was down 3.88 points, or 0.23 percent, at 1,703.08. The Nasdaq Composite Index was down 4.73 points, or 0.12 percent, at 3,671.12.