US hotel group Starwood Capital is to sell four key French properties, including the Martinez in Cannes, the Concorde Lafayette and Hotel du Louvre in Paris and the Palais de la Mediterranee in Nice, to a Qatari investor. A source close to the sale said the buyer was Katara Hospitality, formerly known as Qatar National Hotels Co., which is looking to extend its luxury hotel portfolio. Katara Hospitality notably owns Paris’s luxury Peninsula hotel that is to open next year.