BOSTON -- Summertime blues appear to be here.

Business confidence in the Bay State declined 3.2 points last month to a reading of 48.9 in the Associated Industries of Massachusetts' monthly Business Confidence Index, putting it below the neutral level.

The index, measured through a survey of member business owners, is on a 0-to-100 scale.

In a statement, AIM Board of Economic Advisors Chairman Raymond G. Torto noted that 2013 marked the fourth consecutive summer that the index slumped.

"The only good news is that last year's June decline was much greater, 8.5 points," Torto said. "The bad news, so to speak, is that this year it is more difficult to identify a single reason for the slump."

Torto cited a recent downward revision of growth estimates for the earlier part of 2013 "align with our survey's finding that many Massachusetts employers experienced a slowdown in the first half." He also said weak conditions in Europe, political gridlock and "disturbing (economic) news from China" are other factors.