Lamborghini has admitted it is considering the addition of a four-seater sedan to its line-up to attract customers and allow it to compete with Maserati, Aston Martin and Porsche. The Italian supercar maker currently holds the Gallardo and Murcielago model ranges. CEO Stephan Winkelmann has said there has been no decision on a third model, but has not ruled out the possibility either. “A third model would fit Lamborghini very well,” Winkelmann told Bloomberg. “A four-door car would be a very feasible approach.”Adding four-seater model to the Lamborghini line-up would allow the Sant ‘Agata-based manufacturer to compete against Maserati’s Quattroporte, the Rapide from Aston Martin and the Porsche Panamera. While the carmaker has never produced a sedan, the Espada four-seater coupe formed part of its model range before it was discontinued in 1978. The Estoque concept shown at the 2008 Paris Motor Show, and cloaked in speculation ever since, has never been confirmed for production. An additional model may also help to boost Lamborghini’s fortunes. As the ultra-luxury market experiences a resurgence following the global recession, the company’s first-half sales are down 18% from a year ago. However, Winkelmann said the carmaker aims to double its deliveries to a burgeoning Chinese market to more than 150 units this year.