* Futures up: Dow 99 pts, S&P 11.25 pts, Nasdaq 34.75 pts
By Abhiram Nandakumar
Oct 1 (Reuters) - U.S. stock index futures started the last quarter of the year on a positive note on Thursday as weak data from China raised hopes of more stimulus measures from Beijing and investors awaited a slew of U.S. data.
* Data showed factory activity in China shrank again in September, leading some investors to believe that the government will be more aggressive in its measures to boost the health of the world's second-largest economy.
* Investors will be looking to put a bruising quarter behind them - U.S. stocks posted their worst quarter in four years, while the Shanghai stock market plunged about 25 percent.
* U.S. economic data due on Thursday includes weekly unemployment benefits claims, which are forecast to have risen to 270,000. The data is expected at 8:30 a.m. ET (12:30 GMT).
* Also scheduled for release is Markit's final manufacturing PMI data for September at 9:45 a.m. The index's preliminary reading came in at 53 earlier this month.
* The Institute for Supply Management's index of U.S. factory activity, due at 10:00 a.m., is expected to have fallen to 50.6 in September from 51.1 in August.
* U.S. stocks closed higher on Wednesday as investors bought beaten-down stocks, with biotechs rising for a second day
* U.S. automakers will report sales for September. Analysts expect sales of 17.6 million on an annualized basis, up from 16.5 million last September.
* Investors will be parsing the data being released this week, with the crucial non-farm payroll numbers due on Friday, for clues on the timing of an interest rate hike by the U.S. Federal Reserve.
* The central bank kept rates unchanged at near-zero levels earlier this month as it waits for signs of sustained economic growth before raising rates.
* San Francisco Fed Reserve President John Williams is scheduled to speak on the economic outlook at 2:30 p.m. in Utah.
* Shares of Twitter were down 2 percent at $26.5 premarket after a report that co-founder and interim CEO Jack Dorsey was to be named permanent CEO.
* Celgene was up 1.9 percent at $110.25 after J.P. Morgan raised its rating on the stock to "overweight" from "neutral".
Futures snapshot at 6:47 a.m. ET:
* S&P 500 e-minis were up 11.25 points, or 0.59 percent, with 213,619 contracts traded.
* Nasdaq 100 e-minis were up 34.75 points, or 0.83 percent, on volume of 42,180 contracts.
* Dow e-minis were up 99 points, or 0.61 percent, with 30,715 contracts changing hands. (Reporting by Abhiram Nandakumar in Bengaluru; Editing by Saumyadeb Chakrabarty)