J.Crew Group replaced its chief executive after less than a year in the role, and just a few months after the apparel seller emerged from bankruptcy protection with new hedge-fund owners, the Wall Street Journal reported. Jan Singer, who took over as CEO in February, was replaced Tuesday by Libby Wadle, a longtime J.Crew executive. Neither of them was immediately available for comment. A person familiar with the matter described the change as a board decision meant to simplify the management structure. The two executives had split oversight of the company’s brands, with Ms. Singer overseeing J.Crew and Wadle running Madewell, its faster-growing business. J.Crew filed for bankruptcy protection in May, and emerged in September with a deal that cut its debt and handed ownership to a group of lenders, led by New York hedge fund Anchorage Capital Group LLC. Anchorage co-founder Kevin Ulrich became J.Crew’s chairman.