Formula 1 supremo Bernie Ecclestone says he is close to finalising a contract for the Valencia and Barcelona races to alternate on the calendar from next year - meaning Spain will have just one race from 2013.After months of speculation about the future of the Valencia Grand Prix, Ecclestone revealed that that event and Spanish GP organisers have agreed to share the race from next year.In an interview with Spanish radio station Cadena Ser, Ecclestone said that he was now working on sorting out dates going forward."Both Valencia and Barcelona have agreed that the best way is to alternate, and now we are trying to choose the dates,” explained Ecclestone. "We wanted to see how we could help Valencia, and alternating with Barcelona is a good solution. Sharing the race will be a good idea, providing they are all fine with it.”