By Caroline Humer

Jan 16 (Reuters) - Quest Diagnostics Inc, the No. 1 U.S. clinical laboratory-testing company, said on Wednesday that it would sell one of its diagnostic products business and take a charge of $89.5 million, or 56 cents per share, to write down part of its value and that of another business.

Quest also said that Superstorm Sandy, which caused deaths, flooding, extended widespread power outages and disrupted transportation in the Northeast starting in late October, had hurt fourth-quarter earnings by 6 cents per share and fourth-quarter revenues by $21 million.

Quest had already lowered its outlook for 2012 before the storm, citing slowing growth as consumers have used fewer medical services due to economic pressures and the government and insurers have sought to reduce payments to labs and other providers.

In November, Quest said it would cut costs by $100 million and restructure to restore growth.

On Wednesday, the company said that it would restate 2011 and 2012 results to remove both the HemoCue diagnostic products business and the OralDNA products business, which it sold in December, from continuing operations.

That will reduce 2012 earnings per share by 9 cents and net income from continuing operations by $15 million. It will lower 2012 revenue $117 million.

Analysts expect the company to report earnings of $4.50 per share in 2012 and sales of $7.53 billion, according to Thomson Reuters I/B/E/S.

It will reduce 2011 earnings per share by 8 cents per share and net income from continuing operations by $13 million. It is lowering 2011 revenue by $119 million.

Quest is due to report fourth-quarter earnings on Jan. 23.

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