NEW YORK, Nov 26 (Reuters) - Ascena Retail Group, which owns clothing brands such as Ann Taylor and Loft, said on Thursday it will be acquired by Premium Apparel LLC for $540 million on a cash-free and debt-free basis.

Premium Apparel, a unit of private equity firm Sycamore Partners, has committed to retain a substantial portion of the retail stores and associates affiliated with the brands, Ascena said in a statement.

Other brands under the Ascena Group, Lane Bryant and Lou & Grey, will also be part of Premium Apparel's acquisition.

The transaction is expected to be completed by mid-December, the statement said.

Other Ascena assets - Catherines and Justice - have been already sold off.

FullBeauty Brands Operations has completed its acquisition of the intellectual property assets and e-commerce business of Catherines, while a vehicle formed by Bluestar Alliance has completed its acquisition of the intellectual property of Justice, the statement said.

Ascena filed for chapter 11 protection in July. (Reporting by Gertrude Chavez-Dreyfuss, Editing by Rosalba O'Brien)