Formula One supremo Bernie Ecclestone said Germany could return to the Grand Prix schedule if an agreement was reached with track owners, according to an interview in a German magazine. "I am sitting here with my pen and am prepared to sign a contract if they send me one," Auto Motor und Sport magazine Wednesday quoted Ecclestone as saying. Formula One's governing body, the International Automobile Federation, this year dropped the German Grand Prix from its Formula One calendar for the first time since 1960. The Nuerburgring had been due to host the July 19 race under an alternation agreement but a change of ownership and financial difficulties left Hockenheim as the only option. However, with low attendances at that circuit last year, organizers were unwilling to risk a further loss with so little time to sell tickets and get ready, though they still had a contract to host the race in 2016. "I had hoped that the new owners of the Nuerburgring would be able to agree a contract with me, but that does not appear to be the case," Ecclestone told Auto Motor und Sport. He also cast doubt on whether Hockenheim could continue to shoulder the financial strain of the Grand Prix. "We really have an extremely favorable contract with Hockenheim. That won't be the case in the future anymore. They have to accept what other European countries pay too," he said. Asked whether next year's US Grand Prix in Austin would go ahead, Ecclestone said: "Forecasts are difficult." The Oct. 23 race in Texas, the only round in the United States and important for teams and sponsors, is on the 2016 calendar with an asterisk against it as subject to agreement with the commercial rights holder. "They knew exactly what it would cost when they signed the contract with us. They knew that they would have to build a race track, and what it costs to put on a Grand Prix," Ecclestone said. Ecclestone has said this year that he wanted to add more American venues, but he told the magazine that 2016 would be too soon for a race in California. Nissan withdraws Nissan has withdrawn from next year's World Endurance Championship (WEC), which has the Le Mans 24 Hours as its headline race, after its 2015 car proved uncompetitive. "The teams worked diligently to bring the vehicles up to the desired performance levels," the Japanese company said in a statement. "However, the company concluded that the program would not be able to reach its ambitions and decided to focus on developing its longer term racing strategies." Nissan said their commitment to motorsport remained strong and it would continue to support the WEC through various engine programs. The company returned to the top LMP1 level of the endurance series this year with a front-wheel-drive GT-R LM NISMO car but it was well off the pace at Le Mans, the only race it contested. The 2016 season starts at Silverstone in April, with Porsche the defending champions.