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* Arm extends gains after blockbuster debut

* Instacart raises proposed IPO price range

* Adobe falls on notes offering

* Paramount, Warner Bros up; Byron Allen bids for Disney's ABC

* Indexes down: Dow 0.50%, S&P 0.80%, Nasdaq 1.24%

Sept 15 (Reuters) - The Nasdaq fell more than 1% on Friday to lead declines in Wall Street's main indexes as chipmakers fell on concerns over consumer demand, while rising Treasury yields pressured major growth stocks.

Chip equipment makers Applied Materials, Lam Research and KLA Corp fell around 4% each after Reuters reported TSMC had asked its major vendors to delay deliveries.

Other chipmakers including Nvidia, Advanced Micro Devices, Broadcom and Micron Technology lost between 1.6% and 3.7%, dragging the Philadelphia Semiconductor index to a three-week low.

Also stoking worries over chip demand from automakers, the United Auto Workers' union launched simultaneous strikes at factories of General Motors, Ford and Chrysler parent Stellantis.

Shares of the three automakers, however, rose around 1% each.

Denting sentiment further, U.S. Treasury yields climbed, dragging down growth stocks Amazon, Meta Platforms and Microsoft between 1.8% and 2.7%.

"The Federal Reserve has raised rates very quickly and now they have time to take a look at that and see what impact their policy is having on the economy," said Brian Klimke, chief market strategist at Cetera Investment Management.

"I don't think they're going to give markets what they want next week, they're not going to talk about rate cuts."

Traders' bets on the Fed holding rates steady in its Sept. 20 policy meeting remained intact at 97%, while their odds for a pause in November stood at 67%, according to the CME FedWatch Tool.

Adobe dropped 4.1% to a more than two-week low after the Photoshop software maker disclosed a commercial paper program of up to $3 billion on Sept. 8 following its third-quarter results.

The information technology and consumer discretionary stocks were among the top S&P 500 sectoral losers, down more than 1%.

SoftBank's Arm Holdings gained 1.7% after a stellar Nasdaq debut on Thursday that rekindled hopes of a turnaround in the initial public offering (IPO) market.

Arm's strong debut prompted grocery delivery app Instacart to raise the proposed price range for its IPO to target a fully diluted valuation of up to $10 billion.

Neumora Therapeutics, backed by Amgen and Japan's SoftBank, made a tepid debut at $16.50 per share, lower than its IPO price of $17 per share.

The expiry of quarterly derivatives contracts tied to stocks, index options and futures, also known as "triple witching", later in the day is expected to keep markets volatile.

At 12:25 p.m. ET, the Dow Jones Industrial Average was down 174.87 points, or 0.50%, at 34,732.24, the S&P 500 was down 35.87 points, or 0.80%, at 4,469.23, and the Nasdaq Composite was down 172.92 points, or 1.24%, at 13,753.14.

Paramount Global and Warner Bros Discovery gained 2.4% and 1.7%, respectively, following entrepreneur Byron Allen's $10-billion bid for Walt Disney's ABC TV network. Disney shares were up 1%.

Declining issues outnumbered advancers by a 1.97-to-1 ratio on the NYSE and by a 2.03-to-1 ratio on the Nasdaq.

The S&P index recorded seven new 52-week highs and as many new lows, while the Nasdaq recorded 35 new highs and 143 new lows.

(Reporting by Ankika Biswas and Shristi Achar A in Bengaluru; Editing by Vinay Dwivedi)