A New Hampshire-based developer on Tuesday announced it has purchased two Portland hotels for an undisclosed price. XSS Hotels acquired a controlling interest in the Portland Harbor Hotel and the Inn at Diamond Cove, according to a news release. Bateman Partners, the original developer of both properties, retains a minority ownership in them, the release said. The management affiliate of XSS Hotels, Colwen Hotels, will operate both the 101-room Portland Harbor Hotel, in the city’s Old Port district, and the Inn at Diamond Cove, a 44-room resort on Diamond Island that was recently restored from use as a military barracks.