* Financial shares lead S&P 500
* Indexes up: Dow 1 pct, S&P 1 pct, Nasdaq 1.2 pct (Updates to afternoon, changes byline)
By Rodrigo Campos
June 23 (Reuters) - U.S. stocks rose on Thursday as Wall Street bet strongly that Britain is voting to remain part of the European Union, avoiding a likely hit to Europe's economy and possible consequences to global economic growth.
The results of the referendum, for which polls close at 5 p.m. EDT (2100 GMT), are not yet known. Although bookmakers give the remain camp a more than 80-percent chance of victory, polls continue to show the decision as too close to call.
The British pound rallied against the U.S. dollar, brushing $1.50, but shaved a full percentage point from its earlier gain. It was last up 0.6 percent at $1.4796.
"People are expecting that Britain is going to vote to stay in the EU based on what's happening here, particularly with the fact that financials are leading," said Peter Jankovskis, co-chief investment officer at OakBrook Investments LLC in Lisle, Illinois.
"They view the potential disruption of a British exit as a major financial event. The relief rally, makes sense, would be strongest among those names."
The Dow Jones industrial average rose 168.85 points, or 0.95 percent, to 17,949.68, the S&P 500 gained 20.37 points, or 0.98 percent, to 2,105.82 and the Nasdaq Composite added 57.96 points, or 1.2 percent, to 4,891.27.
The financial sector led the S&P 500 with a 1.7 percent gain.
The CBOE Volatility index fell 14 percent, on track to post its largest daily decline in five months.
Earlier, U.S. jobless claims and factory data pointed to a strengthening economy.
Given the improving economic backdrop, the S&P 500 could hit a record high in the next few days if Britons decide to stay in the EU, Jankovskis said.
"People generally view that as a positive for emerging markets, crude oil, so this suggests this is a rally that would have some legs," he said.
At its session high, the S&P 500 was 1.1 percent below its record closing high hit May last year.
Software maker Twilio Inc nearly doubled in its market debut, rising as high as $29.20 after pricing at $15. It was last up 86.7 percent at $28.01.
Micron Technology added 10 percent at $13.99 in nearly three times the average daily volume of the past 10 days.
The S&P 500 posted 47 new 52-week highs and 2 new lows; the Nasdaq recorded 79 new highs and 20 new lows. (Reporting by Rodrigo Campos; Editing by Nick Zieminski)