UPDATE 1-S&P drops Connecticut GO debt rating to 'A' from 'A-plus'

(Adds details about the rating of Connecticut and its capital city)

NEW YORK, April 13 (Reuters) - S&P Global Ratings on Friday lowered Connecticut's roughly $18.5 billion of general obligation debt outstanding to A from A-plus, citing concerns about the state's increased debt ratio.

The New England state is one of the wealthiest in the country. But its credit rating is among the lowest due to budget problems, underfunded pensions, high debt levels and a dim economic outlook.

"Under our state rating criteria, when a majority of our debt ratios exceeds certain thresholds, our criteria adds an extra one-notch downward adjustment to our overall indicative state rating score," S&P said in a statement about the rating action.

The office of Governor Dannel Malloy was not immediately available for comment.

The so-called credit spread for 10-year Connecticut general obligation bonds over Municipal Market Datas benchmark triple-A yield scale has widened since the beginning of the year from 73 basis points to 88 basis points as of Thursday.

On the same day of the downgrade, S&P said it was upgrading the general obligation debt of Hartford, Connecticut's financially struggling capital city, to A from CCC based on the municipality's recently-struck deal with the state.

Hartford's city council last month approved a program to have the state pay its $540 million of general obligation debt as part of a broader oversight plan that helped the city avoid bankruptcy.

S&P also said it was assigning a BB-plus issuer rating to Hartford. (Reporting by Laila Kearney in New York and Karen Pierog in Chicago; Editing by Richard Chang)