The Singapore Grand Prix is set to stay on the Formula One calendar until 2021, the sport and race organisers confirmed on Friday, after agreeing a four-year contract extension.

Sunday's race in the city-state would otherwise have been the last.

"I'm very glad that all the parties concerned have been able to agree on commercial terms for an extension as Formula One and, I believe, Singapore have been good for each other," Minister for Trade and Industry S. Iswaran told reporters at the Marina Bay street circuit.

"Over the past decade the Singapore race has introduced many innovative elements and become an iconic and highly anticipated event on the F1 calendar," he said.

The sport's first night race is marking its 10th anniversary this year and has established itself as one of the most popular and glamorous of Formula One's events.

Cars drive around a floodlit street circuit through the heart of Singapore against a backdrop of glittering skyscrapers while spectators are entertained by headline music acts. Calvin Harris, Ariana Grande and Seal are on the bill this year.

The race, which will remain 60 percent funded by the government, costs some S$150 million (£82.36 million) to put on every year but Industry Minister Iswaran said that would be going down to S$135 million a year.

It has also contributed S$1.4 billion in tourism receipts to Singapore over the past decade and drawn over 450,000 international visitors, including projected arrivals for this year’s race, according to the Singapore Tourism Board.

Ticket sales for this year's race are 19 percent up.

Formula One Chief Executive Chase Carey described the race as a "signature" event.

"We are very pleased that it will continue to feature on the calendar for a further four years," he added.

Singapore, along with China, had been listed on Formula One's 21-race calendar for next year with an asterisk as subject to confirmation. The new deal removes that doubt and also secures Formula One's future in the region.

Neighbouring Malaysia also hosts a Grand Prix but next month’s race at Sepang is set to be the last.

When asked whether Singapore had come away with a cheaper deal, Carey and Iswaran declined to comment on details.

"We want the Singapore race to be accorded its due importance and position in the context of the F1 calendar because of the value we think it brings to the overall sport," said Iswaran.

"Beyond that the tipping point comes down to a basic analysis of where is the value proposition, can we sustain this going forward and that’s what a lot of the commercial terms were about."