UPDATE: ISM re-corrected the May manufacturing index. The correct figure now stands at 55.4, not 56.0 as previously corrected and reported or 53.2 as originally reported.
Here is the full story below:
The Institute for Supply Management corrected its key manufacturing activity index for May to 55.4, nearly in line with expectations, after economists on Monday said the original release's reading of 53.2 was incorrect.
The report initially suggested a weakening in the pace of factory-sector growth, but economists, including Stone & McCarthy Research Associates, said seasonal adjustments appeared to have been incorrectly applied to the figures.
It took ISM nearly three hours to issue an official statement revising the data. CNBC initially reported the correction would be to a reading of 56.
The 55.4 figure was in line with what Stone & McCarthy said it should be after running the numbers themselves after the initial 10 a.m. EDT (1400 GMT) release.
Kenneth Kim, economist at Stone & McCarthy in Princeton, New Jersey, said he took the numbers from ISM's website but found that his result "wasn't adding up to their (ISM's) reported figures."
He then ran the calculations using the seasonal adjustment factor applied to April's report, not May's, and the numbers were the same as those reported.
"That was confirmation on where the mistake happened," Kim said. He said he reached out to ISM earlier in the day to point out his findings but received no response.