WHITE PLAINS, N.Y. (AP) A major credit rating service has downgraded Westchester County, in suburban New York, to its second-highest level.

Moody's Investment Services attributed the slip from Aaa to Aa1 to a "lack of liquidity." It noted that Westchester is taking part in a program offered by the state to amortize pension payments.

In a statement Wednesday, County Executive Robert Astorino said he chose the state program over layoffs and higher taxes.

He also noted that two other big ratings services, Standard & Poor's and Fitch, have kept the county at their highest rankings. All three firms list Westchester's outlook as "stable."

Astorino said Westchester still has the highest bond ratings of any New York county.