Stewart’s Shops, which is already one of the largest chains of convenience stores in eastern New York, is looking to expand. The company says it’s buying the Jolley convenience store chain, greatly expanding its presence in New England. Stewart’s said the acquisition, which still needs federal regulatory approval, is expected to close by the end of the year. Based in Saint Albans, Vt., Jolley is a family-owned business that operates 45 stores as well as fuel supply and home heating businesses. The stores will continue to operate under the Jolley name, for the time being. Right now, Stewart’s owns and operates about 360 stores. Most are located in upstate New York, but the company own several stores now in southern Vermont.