(For a live blog on the U.S. stock market, click or type LIVE/ in a news window)
* Energy shares rise as oil prices gain
* Healthcare among top gainers across sub-indexes
* U.S. services sector activity contracts in April-ISM
* Indexes up: Dow 1.43%, S&P 500 1.69%, Nasdaq 1.85% (Adds comments, updates prices)
By Medha Singh and Shreyashi Sanyal
May 5 (Reuters) - Wall Street's main indexes jumped on Tuesday as a recovery in oil prices lifted battered energy stocks and a slew of countries eased coronavirus-induced restrictions in an attempt to revive their economies.
Some hard-hit countries, including Italy, as well as a handful of U.S. states are tentatively easing stay-at-home orders this week, raising hopes for a recovery in oil demand.
All the major S&P 500 sub-indexes were trading higher, with the energy sector rising 2.4%, but the index is a big laggard across sectors with a 36.6% decline this year.
Healthcare stocks were also in the spotlight with Pfizer Inc up 2.8% after it announced a venture with its German partner had started delivering doses of its experimental coronavirus vaccines for human testing in the United States.
Regeneron Pharmaceuticals Inc jumped 5.6% as it said its experimental antibody cocktail for COVID-19 may be available for use by the end of summer or fall, as it ramps up efforts to start human trials in June.
Market-leading growth stocks such as Microsoft Corp , Amazon.com Inc and Apple Inc provided the biggest boost for a second day.
The S&P 500 has climbed about 30% from its March lows on the back of unprecedented stimulus measures and signs of a plateau in new COVID-19 cases in many parts of the world.
"We are in the hope mode regarding the rebound that will come once the economies reopen," said Jim McDonald, chief investment strategist for Northern Trust in Chicago.
However, many market experts have warned the rally could be tested amid a risk of another wave of virus infections and with growing evidence of the damage to the economy and corporate America.
Data on Tuesday showed the domestic services sector recorded its first contraction in nearly 10-1/2-years, while the Institute for Supply Management's (ISM) non-manufacturing index showed a smaller-than-expected decline.
Investors are now bracing for data on the labor market through the week with expectations of another staggering initial jobless claims reading on Wednesday and nonfarm payrolls for the month of April due Friday.
"It's all about the mood swings and hopes of the economies reopening. But the problem is this could change once we get to see some of the hard numbers, especially the employment report," said Peter Cardillo, chief market economist at Spartan Capital Securities in New York.
At 12:51 p.m. ET the Dow Jones Industrial Average was up 339.42 points, or 1.43%, at 24,089.18, the S&P 500 was up 47.99 points, or 1.69%, at 2,890.73 and the Nasdaq Composite was up 161.46 points, or 1.85%, at 8,872.18.
Advancing issues outnumbered decliners for a 3.17-to-1 ratio on the NYSE and a 2.54-to-1 ratio on the Nasdaq.
The S&P index recorded eight new 52-week highs and no new low, while the Nasdaq recorded 41 new highs and four new lows. (Reporting by Medha Singh and Shreyashi Sanyal in Bengaluru; Editing by Anil D'Silva, Saumyadeb Chakrabarty and Shounak Dasgupta)