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* Rivian announces it will adopt Tesla charging standard

* New home starts hit 13-month high

* Fed Chair Powell's two-day congressional testimony starts Wed

* Indexes down: Dow 0.52%, S&P 0.33%, Nasdaq 0.12%

NEW YORK, June 20 (Reuters) - Wall Street stocks softened on Tuesday as investors began the holiday-shortened week by taking profits in the wake of a sustained rally amid signs of weakening global demand.

Federal Reserve Chairman Jerome Powell's congressional testimony tomorrow looms as a potential market mover.

All three major U.S. equity indexes were red but off session lows, with oil super-majors Exxon Mobil Corp and Chevron Corp among the heaviest weights.

The broad sell-off comes on the heels of the Nasdaq's longest weekly winning streak since March 2019, and the S&P 500's longest since November 2021.

As of Friday's close, the benchmark S&P 500 had advanced 20% in the last twelve months, and over 14% so far this year.

"We've had a very sharp rise in the market as of late, driven by AI chatter, which has helped the big tech companies," said Tim Ghriskey, senior portfolio strategist Ingalls & Snyder in New York. "It’s been such a sharp rise that some profit taking is natural. At some point, sellers are going to come in and take profits."

Investors now look to Powell's two-day monetary policy testimony before Congress, starting with the U.S. House Financial Services Committee on Wednesday.

"There’s still bearish speculation that the Fed is going to stay higher for longer and won’t lower rates any time soon," Ghriskey added.

Concerns over slowing global demand loomed larger after China cut its lending benchmarks to jump start sluggish demand, which offset a 21.7% surge in housing starts, the largest monthly jump in thirty years.

At 2:23PM ET, the Dow Jones Industrial Average fell 176.8 points, or 0.52%, to 34,122.32, the S&P 500 lost 14.38 points, or 0.33%, to 4,395.21 and the Nasdaq Composite dropped 16.70 points, or 0.12%, to 13,672.88.

Nine of the 11 major sectors of the S&P 500 were lower, led by a 2.4% drop with energy shares plunging, the sector's biggest daily drop of the month so far, as signs of weakening Chinese demand sent crude prices sliding.

Electric vehicle rivals Rivian Automotive Inc and Tesla Inc rose 3.1% and 3.9%, respectively, after Rivian announced it had agreed to adopt Tesla's charging standard.

PayPal Holdings rose 4.0% after KKR & Co agreed to purchase up to 40 billion euros ($43.71 billion) worth of the payments firm's "buy now, pay later" loans in Europe.

Nike slipped 3.5% after Morgan Stanley said it expects margin pressures arising from the company's inventory glut.

U.S.-listed shares of Alibaba Group dropped 4.4% after the e-commerce company announced Daniel Zhang would step down from his roles as CEO and chairman to focus on the company's cloud division.

Adobe Inc fell 2.1% after a report that European antitrust regulators were preparing to investigate the firm's deal to buy cloud-based designer platform Figma.

Dice Therapeutics Inc surged 37.5% after Eli Lilly and Co said it would buy the company in an all-cash deal for about $2.4 billion.

Declining issues outnumbered advancing ones on the NYSE by a 2.11-to-1 ratio; on Nasdaq, a 1.57-to-1 ratio favored decliners.

The S&P 500 posted 11 new 52-week highs and no new lows; the Nasdaq Composite recorded 62 new highs and 74 new lows. (Reporting by Stephen Culp; Additional reporting by Shristi Achar A, Shubham Batra and Johann M Cherian in Bengaluru; Editing by Aurora Ellis)