Economists had expected the confidence index to slip to 99.9.
But both levels are much lower than the national confidence index, which rose almost five points last month, to 88.8.
One year ago, the confidence index for the region stood at 51.
By contrast, the confidence index for the nation as a whole now stands at 118.5, up from 98.4 one year ago.
The confidence index declined to 135.2 from a revised 137.2 in April.
The confidence index reached an all-time high of 144.7 in January 2000.
The board, a business research group, said its confidence index rose to 122.0 last month from 115.8 in January.
The research group's confidence index fell by 5.6 points, to 118.3, its first significant decline this year.
The Conference Board's confidence index fell a sharp six points.
In July, the confidence index reached its highest level since June 2002.
