* Exxon, Chevron biggest drags on S&P 500, Dow
* Weight Watchers soars after Oprah takes stake
* China Q3 GDP data better than expected
* Dow down 0.24 pct, S&P down 0.25 pct, Nasdaq up 0.13 pct (Adds details, changes comment, updates prices)
By Abhiram Nandakumar
Oct 19 (Reuters) - The Dow and S&P 500 indexes were lower on Monday after a slide in oil prices and a swathe of weak quarterly results led by Morgan Stanley but a recovery in healthcare and biotech stocks pushed the Nasdaq Composite up.
The energy index fell 1.7 percent as Brent crude prices slid 2.5 percent to $49.22 per barrel on worries about demand concerns out of China and progress on the nuclear deal with Iran.
Exxon's 1.4 percent fall to $81.30 weighed the most on the S&P 500 while Chevron fell 1.7 percent to $89.71 to be the biggest drag on the Dow Jones industrial average .
Morgan Stanley's shares fell as much as 6.9 percent to $31.60 after the bank's profit fell for the second straight quarter, capping mostly downbeat quarterly results from major U.S. banks. The stock recorded its biggest results-day decline since 2009.
"You've got a market that's really somewhat directionless because you don't have a lot of data points out there that can drive the market up or down," said John Roberts, director of research at Hilliard Lyons.
At 11:02 a.m. ET (1502 GMT), the Dow was down 40.75 points, or 0.24 percent, at 17,175.22, the S&P 500 was down 4.99 points, or 0.25 percent, at 2,028.12 and the Nasdaq composite index was up 6.51 points, or 0.13 percent, at 4,893.20.
Investors will continue scrutinizing company reports this week with several Dow components posting quarterly results, including Caterpillar, Boeing, Amazon and Coca-Cola.
S&P 500 companies are expected to show a 3.9 percent fall in third-quarter profit, according to Thomson Reuters data.
Data on Monday showed China's economic growth slowed to 6.9 percent between July and September, but still ahead of the 6.8 percent forecast.
Data also showed U.S. homebuilder sentiment improved to 64, ahead of the 62 expected.
Halliburton fell 1.7 percent to $37.17 after reporting a bigger-than-expected 36 percent drop in quarterly revenue, hurt by weak drilling activity and pricing in North America.
Weight Watchers surged nearly 90 percent to $12.88 after it said Oprah Winfrey will buy a 10 percent stake in the company and join the board.
PMC-Sierra jumped nearly 14 percent to $11.66 after the chipmaker received a buyout offer from Microsemi, valuing the company at $2.4 billion.
IBM reports quarterly results after the close.
Declining issues outnumbered advancing ones on the NYSE by 1,643 to 1,222. On the Nasdaq, 1,342 issues rose and 1,220 fell.
The S&P 500 index showed 14 new 52-week highs and three new lows, while the Nasdaq recorded 34 new highs and 23 new lows. (Reporting by Abhiram Nandakumar in Bengaluru; Editing by Don Sebastian)