The S&P 500 rose above 1,400 for the first time in nearly four years on data bolstering brighter views of the U.S. economy, while crude settled lower on news that Britain and the United States may release strategic oil stocks to keep growth on track.

U.S. economic growth showed signs of becoming more self-sustaining as the number of Americans claiming new jobless benefits fell back to a four-year low last week and manufacturing activity in the Northeast picked up this month.

The data came two days after the U.S. Federal Reserve offered a slightly more optimistic view of the economy, with some analysts saying policymakers could shy away from more easing as economic expansion picks up.

The Standard & Poor's 500 index <.SPX> hit an intraday high of 1,402.35 and was on track to score a gain for its sixth session out of the last seven.

The 1,400 level confirms the upward bias in the market, said Peter Kenny, managing director at Knight Capital in Jersey City, New Jersey. There is a built-in momentum trend as a result of the economic data.

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Graphic - New York manufacturing:

http://link.reuters.com/tug27s

Graphic: Northeast manufacturing: Philly Fed & Empire State

http://link.reuters.com/fah27s

Graphic - U.S. jobless claims http://link.reuters.com/hug27s

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The Dow Jones industrial average <.DJI> and the Nasdaq <.IXIC> also advanced on Thursday.

Trading was volatile at the start of quadruple witching, the expiration and settlement of four types of equity futures and options contracts.

Shares of Apple Inc hit a record high at $600.01 in early trading, before declining. Some analysts predicted the stock will hit $700 within 12 months.

The Dow Jones industrial average <.DJI> added 34.02 points, or 0.26 percent, to 13,228.12. The Standard & Poor's 500 Index <.SPX> gained 6.64 points, or 0.48 percent, to 1,400.92. The Nasdaq Composite Index <.IXIC> rose 13.16 points, or 0.43 percent, to 3,053.89.

The U.S. data also helped push European stocks to close near 33-week highs.

The FTSEurofirst 300 index <.FTEU3> of top European shares finished up 0.35 percent at 1,102.17, a day after closing at its highest level since August. The index is up 10 percent this year, almost fully recovered from a drop of 10.7 percent last year.

Crude futures fell as much as $3 a barrel after Reuters, citing two British sources, reported that Britain decided to cooperate with the United States in an agreement to release oil from government-controlled strategic reserves. Other countries may also be approached by Washington to contribute, a further source said, Japan among them. A White House spokesman declined comment.

Rising gasoline costs have worried economists, as high prices at the pump pressure U.S. consumers and leave them with less money to spend elsewhere.

But without details of the timing, volume and duration of the emergency drawdown, U.S. crude pared losses.

NYMEX April crude fell for a second day and settled at $105.11 a barrel, down 32 cents, or 0.30 percent, up from a session low of $103.78.

U.S. Treasury prices slipped as stocks' advance and the stronger outlook for the economy eroded the appeal of safe-haven U.S. debt.

The benchmark 10-year U.S. Treasury note dipped 2/32, with the yield at 2.287 percent.

The dollar also fell from an 11-month high against the yen and a one-month high against the euro.

The greenback dropped 0.32 percent to 83.37 yen and the euro advanced 0.54 percent to $1.3097.

(Additional reporting by Edward Krudy; Editing by Dan Grebler, Leslie Adler and Jan Paschal)