* March private sector job additions beat estimates
* All 30 Dow stocks up, index on pace for best day since Mar. 1
* Fed to release March meeting minutes at 2:00 p.m. ET
* Indexes up: Dow 0.84 pct, S&P 0.67 pct, Nasdaq 0.53 pct (Adds details, comments, updates prices)
By Yashaswini Swamynathan
April 5 The Nasdaq Composite hit an all-time high and the Dow was on track for its best day in more than a month following a blowout private employment report that underlined the health of the U.S. economy.
U.S. companies added 263,000 workers in March, the most since December 2014, payrolls processor ADP said on Wednesday. Economists had expected 187,000 jobs to be added in the month.
All of the 11 major S&P 500 sectors were up, with financials and technology giving the biggest boost.
"The GDP number was recently revised upward, jobs continue to look good, inflation is moving in the right direction ...(ADP) was just another piece of the puzzle that gives the market some confidence that we are still on track," said Myles Clouston, senior director at Nasdaq Advisory Services in New York.
The ADP report drew investors back into the market after a period of range-bound trading amid worries about President Donald Trump's ability to deliver on his policy plans after a recent legislative setback.
At 10:58 a.m. ET (1458 GMT), the Dow Jones Industrial Average was up 173.7 points, or 0.84 percent, at 20,862.94 and the S&P 500 was up 15.74 points, or 0.67 percent, at 2,375.9.
The Nasdaq Composite was up 31.48 points, or 0.53 percent, at 5,930.09, slightly below its record high of 5,931.83.
While the ADP report provided some cheer, investors are cautiously awaiting a meeting between Trump and Chinese President Xi Jinping that starts on Thursday.
The meeting, which Trump expects will be a "very difficult one", is likely to focus on North Korea's arms program and China-U.S. trade.
Lofty market valuations - in the wake of the post-election rally - will be tested when the first-quarter earnings season starts next week.
"Valuations from a historical standpoint are in the high end but as long as earnings growth and GDP continue to do well, there is argument that they are justified," Clouston said.
Among stocks, Amazon.com rose as much as 1.5 percent to an all-time high of $920. The online retailer's shares gave the biggest boost to the S&P and the Nasdaq.
Panera Bread jumped nearly 14 percent to $311.90 after JAB Holdings said it would buy the bakery chain for $7.16 billion.
The Federal Reserve will release the minutes of its March policy meeting at 2:00 p.m. ET (1800 GMT).
Advancing issues outnumbered decliners on the NYSE by 1,987 to 792. On the Nasdaq, 1,667 issues rose and 960 fell.
The S&P 500 index showed 31 52-week highs and three lows, while the Nasdaq recorded 55 highs and 29 lows. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Savio D'Souza)