By Reuters Staff (Adds detail) May 7 (Reuters) - French mall owner Klepierre has reopened more than half of its stores and predicts that the vast majority will have opened their doors to customers by the end of May, it said on Friday. On-and-off coronavirus lockdowns over the past year have forced non-essential shops to shut for months at a time and landlords to renegotiate their rental agreements with retailers. “With the expected reopening of our French shopping centres from May 19, close to 95% of our portfolio will soon be open again, albeit with certain restrictions, such as the trading ban at weekends in Italy,” said the chairman of Klepierre’s executive board, Jean-Marc Jestin, in a quarterly earnings statement.