* S&P 500 briefly crosses 3,000 threshold
* Fed's Powell begins two-day testimony before Congress
* Technology biggest boost to indexes
* Stocks briefly extend gains after Fed minutes
* Indexes up: Dow 0.3%, S&P 500 0.5%, Nasdaq 0.8% (Updates close with further comment)
By Caroline Valetkevitch
NEW YORK, July 10 (Reuters) - U.S. stocks ended higher and the S&P 500 index briefly crossed the 3,000-point mark for the first time on Wednesday as remarks by Federal Reserve Chairman Jerome Powell reassured investors about the potential for an interest rate cut later this month.
The Dow also hit an intraday record and the Nasdaq closed at an all-time high following the release of prepared remarks for Powell's testimony before the U.S. House of Representatives Financial Services Committee.
Powell said the central bank stands ready to "act as appropriate" to support record U.S. economic growth.
"It's what the market wanted to hear," said J.J. Kinahan, chief market strategist at TD Ameritrade in Chicago. "Many people thought the jobs report - one data point - would all of a sudden change how the Fed was thinking. But the Fed tends to operate on trends, not data points."
After Powell's remarks and release of the Fed's minutes, interest rate futures appeared to price in greater odds of an aggressive rate cut this month. Expectations for a 50-basis-point cut, which had nearly been snuffed out by stronger-than-expected U.S. employment data on Friday, jumped to 26.6%, according to CME Group's FedWatch tool.
The S&P 500 breached 3,000 just after the opening, but ended slightly below that level at 2,993.07 points. Some investors said the milestone may boost confidence in a market that has been hitting record highs this year.
Amazon.com, Microsoft Corp and Apple Inc were among the biggest boosters to the indexes.
The Dow Jones Industrial Average rose 76.71 points, or 0.29%, to 26,860.2, the S&P 500 gained 13.44 points, or 0.45%, to 2,993.07 and the Nasdaq Composite added 60.80 points, or 0.75%, to 8,202.53.
In his testimony - the first installment of two days on Capitol Hill this week - Powell pointed to "broad" global weakness that was clouding the U.S. economic outlook amid uncertainty about the fallout from the Trump administration's trade dispute with China and other important economies.
Stocks briefly added to gains following minutes from the last meeting of Fed policymakers that showed many U.S. central bank officials thought more stimulus would be needed soon if risks to the economy did not let up.
The S&P 500 index of financial shares including banks, which tend to benefit in a higher interest rate environment, retreated 0.5% after Powell's comments.
Investors say much of this year's gain for stocks has stemmed from a change in outlook by the Fed to more dovish on interest rate policy.
"On balance, investors live by the credo: 'Don't fight the Fed,' and if rates are being cut - whatever the reason - they have often stood by stocks, so I'm not surprised we're making new highs," said Rick Meckler, partner, Cherry Lane Investments, a family investment office in New Vernon, New Jersey.
"But it's a market that's come an awfully long way. And I think you're running out of investors willing to put too much new money in without some indication that earnings can stay strong."
Advancing issues outnumbered declining ones on the NYSE by a 1.92-to-1 ratio; on Nasdaq, a 1.19-to-1 ratio favored advancers.
The S&P 500 posted 73 new 52-week highs and two new lows; the Nasdaq Composite recorded 99 new highs and 43 new lows.
Volume on U.S. exchanges was 6.38 billion shares, compared to the 6.72 billion average for the full session over the last 20 trading days.
Reporting by Caroline Valetkevitch; additional reporting by April Joyner in New York and Medha Singh, Manas Mishra and Shreyashi Sanyal in Bengaluru; editing by Bill Berkrot