A measure of future U.S. economic growth weakened in the latest week to the lowest level in nearly five months, while the annualized growth rate also faltered, a research group said on Friday. 

The Economic Cycle Research Institute, a New York-based independent forecasting group, said its Weekly Leading Index fell to 122.4 in the week ended May 25 from 123.0 the previous week. That was originally reported as 123.1. 

It was the lowest level since early January, ECRI said. 

The index's annualized growth rate fell to minus 0.6 percent from 0.1 percent a week earlier.