Standard & Poor's managing director John Chambers said on Sunday there is a one in three chance of a further U.S. credit rating downgrade over the next six months to two years.

We have a negative outlook ... from six months to 24 months, he said on ABC's This Week.

And if the fiscal position of the United States deteriorates further or if the political gridlock becomes more entrenched, then that could lead to a downgrade. The outlook indicates at least a one in three chance of a downgrade over that period.

Chambers said that it would take some time for the United States to recover its AAA rating.

It would take a stabilization of the debt as a share of the economy and eventual decline. And it would take, I think, more ability to reach consensus in Washington than what we're observing now, he said.

(Reporting by Jackie Frank; Editing by Doina Chiacu)