* U.S. crude drops to lowest level in a year
* Pound higher on reports of finalized Brexit agreement text
* Euro rises off lowest levels since mid-2017
* U.S. dollar lower but remains near 16-month high (Updates prices, market activity, comments to mid-afternoon trade in U.S. markets)
By April Joyner
NEW YORK, Nov 13 (Reuters) - Wall Street stock prices shed earlier gains on Tuesday while oil prices plunged on persistent concerns of weakening global demand.
The U.S. benchmark S&P 500 stock index turned negative after energy stocks were depressed by falling Brent and U.S. crude futures. Oil prices tumbled 7 percent, with U.S. crude touching its lowest level in a year.
Brent and U.S. crude extended their fall from Monday after U.S. President Donald Trump put pressure on OPEC not to cut supply to prop up prices. Both crude benchmarks have fallen more than 20 percent since peaking at four-year highs in early October.
"It's like a run on the bank," said Phil Flynn, analyst at Price Futures Group in Chicago. "It's getting to the point where it doesn't seem to be about fundamentals anymore, but a total collapse in price."
U.S. natural gas futures, however, soared to their highest since November 2014 on forecasts for colder weather.
Earlier, U.S. stocks had risen after White House Economic Adviser Larry Kudlow said Washington had resumed trade talks with China and characterized the development as "very positive." Technology stocks bounced back a day after a rout that led the S&P 500's nearly 2 percent decline.
The U.S. dollar index, which has steadily climbed as the U.S.-China trade dispute has escalated, dipped 0.2 percent.
"To the extent that we get movement in the tariff discussion the market will view that as a positive," said Bucky Hellwig, senior vice president at BB&T Wealth Management in Birmingham, Alabama.
The pound rose 0.8 percent to $1.2953 after reports that the United Kingdom and the European Union had agreed upon the text of a Brexit agreement and that British Prime Minister Theresa May would hold a cabinet meeting on Wednesday.
The euro also rose from a 16-month low, last up 0.4 to $1.1264, though its gains were capped by concerns over Italy's budget and downbeat German investor sentiment data.
The Dow Jones Industrial Average fell 112.53 points, or 0.44 percent, to 25,274.65, the S&P 500 lost 3.22 points, or 0.12 percent, to 2,723 and the Nasdaq Composite added 3.79 points, or 0.05 percent, to 7,204.66.
MSCI's gauge of stocks across the globe shed 0.12 percent.
Benchmark 10-year U.S. Treasury notes last rose 12/32 in price to yield 3.1452 percent, from 3.189 percent late on Friday. The Treasury market was closed on Monday for the Veterans Day holiday.
U.S. crude fell 7.88 percent to $55.21 per barrel and Global benchmark Brent crude fell $5.12 a barrel to a session low of $65 a barrel in post-settlement trade.
But front-month gas futures on the New York Mercantile Exchange jumped 7.7 percent. (Reporting by April Joyner; Additional reporting by David Gaffen and Stephen Culp in New York and Tom Finn and Marc Jones in London; Editing by David Gregorio and Cynthia Osterman)