* November factory activity, auto sales expected
* Chicago Fed's Evans to speak later in the day
* Mattress Firm up after agreeing to buy Sleepy's owner
* Indexes up: Dow 0.57 pct, S&P 0.61 pct, Nasdaq 0.50 pct (Updates to open)
By Tanya Agrawal
Dec 1 (Reuters) - Wall Street kicked off the last month of the year on a positive note as investors await data and policy decisions by central banks.
A barrage of data is expected later in the day, including U.S. factory activity data for November at 10 a.m. ET (1400 GMT), which is expected to tick up. The Department of Commerce is likely to report a slight dip in construction spending for October and automakers will report sales figures for November.
U.S. auto sales are expected to rise above 18 million vehicles on an annualized basis for November, continuing the pace for record sales in 2015.
Investors are keeping an eye on data for clues regarding the health of the U.S. economy that might enable the Federal Reserve to raise interest rates for the first time in nearly a decade.
The main data this week is the November employment report, which is expected to show that the economy added 200,000 jobs during the month. Analysts say a strong report virtually guarantees a rate rise this month.
At 9:39 a.m. ET the Dow Jones industrial average was up 100.75 points, or 0.57 percent, at 17,820.67, the S&P 500 was up 12.64 points, or 0.61 percent, at 2,093.05 and the Nasdaq Composite was up 25.50 points, or 0.5 percent, at 5,134.17.
All 10 major S&P sectors were higher with the financial index's 0.91 percent rise leading the advancers. JPMorgan's 1.4 percent rise gave the biggest boost to the S&P.
Chicago Fed President Charles Evans is scheduled to speak at an event at 12:45 p.m. ET. Evans is a voting member of this year's Federal Open Market Committee. Chair Janet Yellen is scheduled to speak on Wednesday and Thursday.
Investors are also awaiting a European Central Bank meeting on Thursday, when the central bank is widely expected to ramp up its trillion-euro bond-buying program.
"Overall sentiment remains bullish," Markus Huber, senior analyst at Peregrine & Black, said.
"However, in light of this week's crucial ECB meeting, Fed chief Yellen testifying on Capitol Hill and Friday's U.S. non-farm payroll, it wouldn't come as too much of a surprise if investors, instead of typically pouring additional new money into stocks at the beginning of a new month, might hold off until next week."
Stocks were also helped by tentative signs that a slowdown in China was stabilizing.
Private data showed Chinese factory activity contracted at a slower pace than in October, fuelling hopes the economy may have been bolstered by government support.
TerraForm Power rose 18.7 percent to $8.19 after Oppenheimer upgraded its rating to "outperform".
Infoblox jumped 19.8 percent to $18.01, a day after the network management services provider's second-quarter profit and revenue forecast beat expectations.
Mattress Firm Holding was up 8.9 percent at $53.78, a day after the company agreed to buy HMK Mattress Holdings, the owner of mattress retailer Sleepy's, for about $780 million.
Advancing issues outnumbered decliners on the NYSE by 2,092 to 600. On the Nasdaq, 1,411 issues rose and 836 fell.
The S&P 500 index showed 15 new 52-week highs and 3 new lows, while the Nasdaq recorded 44 new highs and 16 new lows. (Reporting by Tanya Agrawal; Editing by Don Sebastian)