A measure of future U.S. economic growth edged up in the latest week, while the annualized growth rate improved slightly, a research group said on Friday.

The Economic Cycle Research Institute, a New York-based  independent forecasting group, said its Weekly Leading Index  edged up to 123.3 in the week ended August 17 from a revised 123.0 the prior week. That was originally reported as 122.8.

The index's annualized growth rate rose to -0.1 percent from the prior week's -0.4 percent, which was originally reported as -0.6.