PARIS (Reuters) -Airbus is grappling with a growing shortfall in the range of its upcoming A321XLR passenger jet after reaching an agreement with European regulators on design safeguards needed to achieve certification, industry sources said. "Airbus expects no significant impact on the XLR’s unique range advantage in the single-aisle segment," an Airbus spokesperson said in response to a Reuters query. Launched in 2019 to expand on the successful A321neo jet and steal a march on Boeing's plans to build a new jet in the middle of the market, which were later abandoned, the A321XLR made its air show debut at Le Bourget outside Paris last month.