Shares of

Pediatrix Medical

(PDX)

were down about 35% for the week after the company said on Monday that the

Federal Trade Commission

had requested information relating to the company's $190 million acquisition of Magella Healthcare. Pediatrix, which runs a network of physician group practices, said the inquiry shouldn't be viewed as an indication of wrongdoing, but the company said it can't predict if the investigation will impact its business. Magella had been Pediatrix's only major national rival until it was acquired last year