* Jobless claims stay near 15-year low
* Alibaba jumps on better-than-expected results
* Yelp jumps on report of sale
* Indexes up: Dow 0.6 pct, S&P 0.4 pct, Nasdaq 0.6 pct (Updates to early afternoon)
By Tanya Agrawal
May 7 (Reuters) - U.S. stocks moved higher on Thursday afternoon, helped by strong results from Alibaba, a rebound in tech stocks and as upbeat jobless claims data indicated the labor market was improving despite moderate economic growth.
The three major indices were poised to end two straight sessions of losses, exacerbated on Wednesday by Federal Reserve Chair Janet Yellen's comments that equity valuations "generally are quite high".
The number of Americans filing new claims for unemployment benefits held near a 15-year low last week, suggesting positive momentum in the economy, even though growth stumbled badly last quarter.
Expectations for a relatively strong nonfarm payrolls report for April were also bolstered by a separate report showing small businesses increased hiring last month.
"A lot of the market is really focused on Friday's payroll report which should give us a good indication if the weak first-quarter data was really due to just weather," said David Carter, chief investment officer at Lenox Wealth Advisors in New York.
Wall Street had a choppy start to the session as Yellen's comments and the continued sell-off in the global bonds weighed on investors.
At 13:22 p.m. EDT (1722 GMT) the Dow Jones industrial average was up 99.73 points, or 0.56 percent, at 17,941.71, the S&P 500 was up 8.86 points, or 0.43 percent, at 2,089.01 and the Nasdaq Composite was up 28.43 points, or 0.58 percent, at 4,948.07.
Nine of the 10 S&P 500 sectors were positive, led by the technology index's 0.8 percent gain, which put it on track to close higher for the first time this week.
Microsoft and Apple gave the biggest boost to the S&P 500 and the Nasdaq, while Yahoo rose 4.7 percent to $43.64 on Alibaba's strong results.
Alibaba's shares jumped 7.5 percent to $86.02 as the Chinese e-commerce giant reported a better-than-expected rise in quarterly revenue.
Yelp soared 12.6 percent to $42.75 after the Wall Street Journal reported that the operator of consumer review website Yelp.com is exploring a sale.
Oil prices fell, after touching their highest in 2015 on Wednesday, putting pressure on airline stocks and pushing the energy index down 1.2 percent.
United Continental rose 4.4 percent, while American Airlines was up 4.6 percent and Delta gained 4 percent.
Whole Foods slid 10.3 percent to $42.79 and was the biggest loser on the S&P after the company said same-store sales growth cooled in the latest quarter.
Advancing issues outnumbered declining ones on the NYSE by 1,733 to 1,269, for a 1.37-to-1 ratio on the upside; on the Nasdaq, 1,566 issues rose and 1,101 fell for a 1.42-to-1 ratio favoring advancers.
The benchmark S&P 500 index was posting 6 new 52-week highs and 2 new lows; the Nasdaq Composite was recording 39 new highs and 49 new lows. (Editing by Savio D'Souza)