NEW YORK – Standard & Poor’s Ratings Services has cut the credit rating of UnumProvident Corp. to “junk” grade, following the latest earnings results from the disability insurance provider.

S&P on Thursday lowered its counterparty credit and senior debt ratings on the Chattanooga, Tenn., company one notch to double-B-plus.

The rating agency also cut its counterparty credit and financial strength ratings on UnumProvident’s insurance operating subsidiaries to triple-B-plus from single-A-minus. The outlook is “stable.”

S&P said the downgrades were due to concerns about the “consistency of risk controls and valuation practices.” It cited large reserve charges and asset impairments in the past several quarters, including the $856 million of intangible impairments and $111 million reserve strengthening included in the company’s first-quarter earnings announcement Wednesday.

Shares of UnumProvident closed Thursday at $14.74, down $1.19, or 7.5 percent, on the New York Stock Exchange.

UnumProvident reported a first-quarter loss due to charges for restructuring some of its individual income protection business.

The company said the loss for the first quarter widened to $562.3 million, or $1.91 a share, from the prior year’s $246.4 million, or $1.02 a share.

The charges for impairment of intangible assets and reserve boosts amounted to $2.57 a share.

First-quarter revenue increased to $2.62 billion from $2.39 billion last year.

Fitch Ratings, another credit rating service, Thursday said it still rates UnumProvident’s senior debt at the lowest investment-grade level. The company remains on “Rating Watch Negative,” where it was placed after it announced a boosting of reserves in February.