US STOCKS-S&P 500 falls, still on track for third straight month of gains

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* Twitter plunges on dull second-quarter outlook

* Chevron down as profit drops on weaker refining margins

* U.S. consumer spending rebounds in March

* Indexes down: Dow 0.61%, S&P 0.57%, Nasdaq 0.40% (Updates prices to early afternoon)

By Shivani Kumaresan and Shreyashi Sanyal

April 30 (Reuters) - The S&P 500 fell in early afternoon trading on Friday, after a slew of strong quarterly earnings and upbeat economic data put the benchmark index on track for a third straight month of gains.

The Nasdaq .IXIC is set for six consecutive months of gains, boosted by impressive results from big technology companies. The Dow Jones Industrial Average .DJI is on course to end in the positive territory for three months in a row.

Amazon.com Inc AMZN.O rose 1.1% after it posted record profit and signaled that consumers would keep spending in a growing U.S. economy and converts to online shopping are not likely to leave. Inc TWTR.N plunged 12.8% as it offered tepid revenue forecast for the second quarter, saying user growth could slow as the boost seen during the pandemic fizzles. high-flying stocks including Microsoft Corp MSFT.O , Facebook Inc FB.O , Alphabet Inc GOOGL.O and Apple Inc AAPL.O fell between 0.3% and 1.5%.

Even though megacap favorites posted largely upbeat earnings in the first quarter, their shares have struggled to maintain the upward trajectory they had coming into reporting season.

"I think we are overdone. I don't think all of these gains are going to continue and that the optimism is going to go beyond what's reasonable to expect," said Mike Zigmont, head of trading at Harvest Volatility Management.

Nine of the 11 major S&P 500 sectors were trading lower, with technology .SPLRCT , materials .SPLRCM and energy .SPNY falling more than 1% each.

Of the 303 companies in the S&P 500 that have reported so far, 87.1% have topped analysts' earnings estimates, with Refinitiv IBES data now predicting a 46.3% jump in profit growth.

Data on Friday showed U.S. consumer spending rebounded in March amid a surge in income as households received additional COVID-19 pandemic relief money from the government. 12:01 p.m. ET the Dow Jones Industrial Average .DJI was down 209.03 points, or 0.61%, at 33,851.33, the S&P 500 .SPX was down 23.99 points, or 0.57%, at 4,187.48 and the Nasdaq Composite .IXIC was down 55.84 points, or 0.40%, at 14,026.70.

Chevron Corp (NYSE: CVX ) CVX.N shed 3% after its first-quarter profit fell 29%, hit by weaker refining margins and production losses. Inc ABBV.N rose 0.5% as it reported strong results and raised its 2021 earnings forecast, helped by demand for its rheumatoid arthritis drug in the United States.

Declining issues outnumbered advancers for a 2.12-to-1 ratio on the NYSE and for a 1.98-to-1 ratio on the Nasdaq.

The S&P index recorded 44 new 52-week highs and no new low, while the Nasdaq recorded 52 new highs and 26 new lows.