US STOCKS-Futures up, indexes on track for 4th week of gains
* Trading expected to be light ahead of holiday
* Indexes on track for fourth straight week of gains
* Chicago PMI, consumer sentiment data on tap
* Futures up: Dow 15 pts, S&P 2.5 pts, Nasdaq 7.25 pts (Updates prices, adds economic data)
By Ryan Vlastelica
NEW YORK, Aug 29 (Reuters) - U.S. stock index futures pointed to modest gains at the open on Friday, indicating the market's recent upswing was intact with major indexes on track for their fourth straight week of gains.
* Stocks have been strong of late, with investors taking any opportunity to buy on dips. However, this week's trading volume has been among the lightest of the year, and that is likely to be more pronounced on Friday, ahead of the Labor Day holiday in the United States for which markets will be closed on Monday.
* In the latest economic data, consumer spending unexpectedly fell in July as savings rose to their highest level in more than 1-1/2 years, a sign that households remain cautious despite an acceleration in economic and jobs growth.
* After the market opens, the MNI Chicago Purchasing Manager's Index and the Thomson Reuters/University of Michigan Surveys of Consumers will be released. Both are seen rising modestly. Continuación...