* 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 up 0.1 pct, S&P up 0.03 pct, Nasdaq up 0.4 pct (Updates close with IBM, Rambus down after the bell, the latest volume)
By Caroline Valetkevitch
Oct 19 (Reuters) - Advances in top tech and biotech names helped U.S. stocks to end with slight gains on Monday, while caution at the start of a heavy week of earnings kept a lid on the market.
The Dow and S&P 500 pared losses late in the session while the Nasdaq added to gains. Nike, up 2.1 percent, helped the Dow, while gains in Apple and Intel supported all three major indexes.
Intel was up 1.7 percent at $33.59, while Apple was up 0.6 percent at $111.73. After the bell, shares of IBM dropped 4.9 percent to $141.94, while Rambus fell 10.2 percent to $12.48, each following results.
During the regular session, the Nasdaq Biotech Index was up 0.6 percent.
The energy index fell 1.9 percent as U.S. crude oil fell 2.9 percent. Copper fell after data showed a slowdown in China's economic growth.
Exxon slipped 1.8 percent to $80.99 and Chevron fell 1.4 percent to $90.03, the biggest drags on the S&P 500 and the Dow.
"Energy and oil prices were down today, and the industrials and materials sectors were among the laggards, so that took a little bit off the enthusiasm for equities," said Mark Luschini, chief investment strategist at Janney Montgomery Scott in Philadelphia.
"After such a significant rally, we're back at a level where we anticipated we'd see a little pressure."
Morgan Stanley's shares fell 4.8 percent to $32.32. The bank's profit fell for the second straight quarter, capping mostly downbeat quarterly results from major U.S. banks.
The Dow Jones industrial average rose 14.57 points, or 0.08 percent, to 17,230.54, the S&P 500 gained 0.55 points, or 0.03 percent, to 2,033.66 and the Nasdaq Composite added 18.78 points, or 0.38 percent, to 4,905.47.
U.S. stocks posted their third straight week of gains on Friday.
Several Dow components are posting quarterly results this week, including Caterpillar, Boeing and Coca-Cola . S&P 500 earnings are expected to have declined about 4 percent in the third quarter from a year ago, according to Thomson Reuters data.
China's economic growth slowed to 6.9 percent between July and September, still ahead of the 6.8 percent forecast.
U.S. homebuilder sentiment improved in October, with the NAHB/Wells Fargo Housing Market index rising more than expected. An index of housing shares was up 0.3 percent.
Weight Watchers more than doubled in value to $13.92 after it said Oprah Winfrey will buy a 10-percent stake in the company and join its board.
Declining issues outnumbered advancing ones on the NYSE by 1,655 to 1,421, for a 1.16-to-1 ratio on the downside; on the Nasdaq, 1,382 issues rose and 1,381 fell for a 1.00-to-1 ratio favoring advancers.
The S&P 500 posted 22 new 52-week highs and 3 new lows; the Nasdaq recorded 53 new highs and 40 new lows.
About 6.0 billion shares changed hands on U.S. exchanges, compared with the 7.3 billion daily average for the past 20 trading days, according to Thomson Reuters data. (Editing by Nick Zieminski and Chris Reese)