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* Tesla, Microsoft results expected

* Record existing home sales jump boosts housing stocks

* Snap Inc falls after disappointing user growth forecast

* Dow up 0.18%, S&P rises 0.16%, Nasdaq down 0.18% (New throughout, updates prices, market activity and comments to late afternoon, changes dateline, byline)

NEW YORK, July 22 (Reuters) - U.S. stock indexes traded mixed and in a narrow range on Wednesday as investors digested mixed quarterly results, stimulus negotiations in Washington and simmering U.S.-China tensions.

The blue-chip Dow the S&P 500 oscillated between positive and negative territory and were last slightly higher. The Nasdaq dipped, pressured by a 1.6% drop in Amazon.com shares.

The S&P 500 remains positive territory year-to-date, up nearly 1%. The Nasdaq has gained more than 18% since Jan. 1, while the Dow remains down almost 6%.

"Investors are still trying to figure out which way to go," said Tim Ghriskey, chief investment strategist at Inverness Counsel in New York. "There's so much uncertainty out there."

The latest figures showed more than 1,000 deaths in the United States from COVID-19 on Tuesday, bringing the total death toll to nearly 142,000. Experts warned that number will rise further due to a surge in new infections.

Congressional Democrats and Republicans remained divided on the details of a new stimulus package expected to cost $1 trillion or more, less than two weeks before extended benefits are due to expire for millions of unemployed Americans.

"Talk of a big stimulus package is sending jitters through the market because of the swelling deficit," Ghriskey added. "On the other hand stimulus package benefits the economy and we all know this economy needs help during this pandemic."

Strained relations between Washington and Beijing deteriorated more after the White House abruptly shut down a Chinese consulate in Houston, a move China called "unprecedented."

On the economic front, sales of existing homes jumped by a record 20.7% in June, according to the National Association of Realtors.

The Philadelphia SE Housing index was up 2.2%, handily outperforming the broader market.

The Dow Jones Industrial Average rose 48.2 points, or 0.18%, to 26,888.6, the S&P 500 gained 5.14 points, or 0.16%, to 3,262.44 and the Nasdaq Composite dropped 18.92 points, or 0.18%, to 10,661.45.

Seven of the 11 major sectors in the S&P 500 trading higher, with utilities enjoying the biggest percentage gain.

Second quarter earnings season is in full-swing, with 75 constituents of the S&P 500 having posted results. Of those, 77.3% have beaten consensus, according to Refinitiv data.

But expectations have set a low bar. Analysts now see aggregate S&P 500 second quarter earnings plunging by 41.2% year-on-year, per Refinitiv.

Pfizer Inc gained 4.5% after the drugmaker and German biotech firm BioNTech SE announced the U.S. government would pay $1.95 billion 100 million doses of their COVID-19 vaccine candidate.

Hospital operator HCA Healthcare Inc reported better-than-expected quarterly revenue, sending its stock jumping 11.4%.

Snap Inc shares sank 7.0% after posting a net loss of $326 million and forecasting fewer-than-expected current-quarter users.

Shares of United Airlines Holdings Inc dropped 3.2% after the company reported an adjusted net loss of $2.6 billion in the April to June quarter.

Market participants now look to quarterly results from Microsoft Corp and Tesla Inc, both due after the closing bell.

Advancing issues outnumbered declining ones on the NYSE by a 1.16-to-1 ratio; on Nasdaq, a 1.45-to-1 ratio favored decliners.

The S&P 500 posted 38 new 52-week highs and 1 new lows; the Nasdaq Composite recorded 75 new highs and 10 new lows. (Reporting by Stephen Culp; Editing by David Gregorio)