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* IBM tumbles after missing quarterly revenue estimates

* Tesla trades higher after Q3 report

* Indexes: Dow down 0.41%, S&P off 0.06%, Nasdaq up 0.29%

Oct 21 (Reuters) - The Dow fell on Thursday as IBM shares collapsed after a disappointing quarterly report, but the Nasdaq advanced with help from defensive big technology companies and Tesla Inc.

The benchmark S&P 500 index was very slightly in the red after six straight sessions of gains, but was just about 10 points short of its early September record.

After hitting an intraday record on Wednesday the Dow pulled back, with IBM down 9% after missing Wall Street estimates for quarterly revenue as orders in one business segment declined ahead of a spinoff next month.

Seven of the 11 major S&P 500 sectors were trading lower, with energy stocks declining the most as crude oil futures fell on concerns about weak winter demand.

Consumer discretionary was the biggest percentage gainer among the S&P sectors so far, with help from Amazon.com Inc.

"For the most part you're dealing with a slightly risk-off day with people going back to more defensive sectors" including big technology companies, said Chris Zaccarelli, chief investment officer at Independent Advisor Alliance in Charlotte, North Carolina.

"You're seeing oil down a little bit today so potentially there's some global growth concerns. You're seeing some inflation concerns as well."

By 2:14 p.m. EDT, the Dow Jones Industrial Average fell 144.57 points, or 0.41%, to 35,464.77, the S&P 500 lost 2.64 points, or 0.06%, to 4,533.55 and the Nasdaq Composite added 43.98 points, or 0.29%, to 15,165.65.

Investors are keeping an eye out for growth outlook comments from companies facing rising costs, labor shortages and supply-chain constraints, with analysts expecting S&P 500 third-quarter earnings to rise 33.7% year-on-year, according to Refinitiv.

"They (supply-chain constraints) definitely are a concern. Things like semiconductor chips in particular have held back the economy to some degree and have put some upward pressure on inflation," said Jon Adams, senior investment strategist for BMO Global Asset Management.

Tesla was the Nasdaq's biggest boost, erasing early declines to rise 3.0% as investors digested the electric car maker's upbeat earnings, despite a supply-chain warning.

Data showed the number of Americans filing new claims for unemployment benefits dropped to a 19-month low last week, pointing to a tightening labor market, though a shortage of workers could keep the pace of hiring moderate in October.

American Airlines rose 1.5% after posting a smaller-than-expected quarterly loss, while Southwest Airlines Co fell 1.8% after it said it expected current quarter profit to remain elusive.

HP Inc gained 5.7% as brokerages raised their price targets on the stock after the personal computer and printer maker forecast upbeat fiscal 2022 adjusted profit and raised its annual dividend.

Declining issues outnumbered advancing ones on the NYSE by a 1.59-to-1 ratio; on Nasdaq, a 1.12-to-1 ratio favored decliners.

The S&P 500 posted 51 new 52-week highs and no new lows; the Nasdaq Composite recorded 93 new highs and 33 new lows. (Reporting by Shreyashi Sanyal and Devik Jain in Bengaluru, Sinéad Carew in New York Editing by Arun Koyyur and Matthew Lewis)