US STOCKS-Wall St flat; energy shares, Morgan Stanley results weigh
* Morgan Stanley leads weak results on Monday
* Exxon, Chevron drag down S&P 500, Dow
* Weight Watchers soars after Oprah takes stake
* China Q3 GDP data weighs on commodities
* Dow down 0.04 pct, S&P down 0.1 pct, Nasdaq up 0.2 pct (Updates to late afternoon)
By Caroline Valetkevitch
Oct 19 (Reuters) - Weak quarterly results from Morgan Stanley and sliding oil prices weighed on U.S. stocks in late trading Monday, offsetting a rebound in biotech shares.
The energy index fell 2.2 percent as U.S. crude oil fell 2.9 percent. Copper fell after data showing a slowdown in China's economic growth.
Exxon and Chevron fell 2 percent and were the biggest drags on the S&P 500 and on the Dow Jones industrial average. Continuación...