Slide in energy companies moves US stocks modestly lower

Major U.S. stock indexes shifted lower in midday trading today after spending much of the morning wavering between small gains and losses.

Investors were weighing the latest batch of company earnings news and looking ahead to the beginning on Wednesday of two days of testimony before Congress by Federal Reserve Chairwoman Janet Yellen. European markets fell following steep losses in Japan.

The Dow Jones industrial average was down 82 points, or 0.5 percent, to 15,944 as of 12:18 p.m. Eastern Time. The Standard & Poor's 500 slipped eight points, or 0.5 percent, to 1,844. The Nasdaq composite fell 17 points, or 0.4 percent, to 4,266. Stocks posted steep slides Monday and Friday.

"The market has been trying to define a direction, leadership," said Quincy Krosby, market strategist for Prudential Financial. "But the pockets of uncertainty continue. That's part of what's holding the market back."

Five of the 10 sectors in the S&P 500 index moved lower, with energy and telecommunications services stocks posting the biggest decliners. Materials stocks led the gainers.