NEW YORK (AP) -- Mayor Bloomberg's administration says New York City's carbon count decreased slightly in 2009.

A City Hall analysis concludes the city emitted 49.3 million metric tons of greenhouse gases, a 4.2 percent reduction from 2008's level of 51.5 million metric tons.

A report released Thursday says the main factor is cleaner imported power. The city is getting less carbon-intensive electricity after an upstate coal-fired power plant reduced its power generation.

And New Yorkers used less heating oil and less electricity.

The carbon count dipped despite a larger population and growing building stock.

The count is determined by collecting and analyzing data from a variety of sources, including utility companies, transit authorities and city agencies.

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