(Bloomberg) -- Moody’s Investors Service has cut its outlook for U.S. regulated utilities to negative from stable for the first time as debt levels rise and cash flows dwindle.

The overhaul of the U.S. tax code signed by President Donald Trump leaves utilities able to collect less cash from customers at a time when their debt has reached its highest levels since the financial crisis a decade ago, Moody’s analysts led by Ryan Wobbrock wrote in a research note Monday. The ratio of funds from operations to debt for the sector is forecast to decline from 17 percent at the end of 2017 to 15 percent through 2019, Moody’s said.

“Regulated utilities will be exposed to a higher level of financial risk for the next 12 to 18 months” Wobbrock said in a statement.

The Standard and Poor’s 500 Utilities Index was up 0.4 percent at 3:57 p.m. in New York.

To contact the reporter on this story: Mark Chediak in San Francisco at mchediak@bloomberg.net

To contact the editors responsible for this story: Lynn Doan at ldoan6@bloomberg.net, Joe Ryan, Will Wade

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