Renault team boss Eric Boullier says F1 should look into alternating races on the calendar in order to make room for a number of new events that are set to join the calendar in the coming years.

Next season the calendar will go up to 20 races, the most there has been in a season, although question marks exist over a number of events including Bahrain and Korea.

Looking further down the line, New Jersey is set to join the schedule in 2013 while a Russian GP is due to start in 2014, although that date could yet be moved back a year due to a clash with the Winter Olympics in the resort of Sochi.

The continued expansion of F1 into new markets has put the future of some of the more traditional European events at risk, but with concerns over the possibility of the calendar becoming too large [See separate story HERE] Boullier said it may be time to consider alternating races - as is the case with the race in Germany which switches between Hockenheim and the Nurburgring.

A similar approach could be taken in Spain to alternate between Catalunya and Valencia, while it would provide the chance for a nation like France to return to the calendar - possibly in a deal to alternate with the Belgian Grand Prix at Spa.

"There is a slot to take because we are talking about alternating with another European grand prix so it doesn't affect too much the number of races," he told Reuters. "I think some European grands prix can afford one race every two years rather than a race every year. So this could be a good way of keeping different track locations in Europe."