An estimated 400,000 people were at Woodstock in 1969
Woodstock promoter Michael Lang has abandoned plans for a free 40th anniversary gig after failing to find funding, Rolling Stone has reported.
The US magazine said Mr Lang, one of four founders of the legendary festival, had failed to find sponsors to cover costs of up to $10m (£5.9m).
He hoped to stage the gig in New York's Climate Week in September, it said.
Jimi Hendrix closed the original event in Bethel, New York State, which took place from 15 to 18 August 1969.
Rolling Stone said Mr Lang had initially planned a concert in Brooklyn's Prospect Park during August.
When that fell through, he had hoped to stage a festival to coincide with Climate Week NYC, which will run from 20 to 25 September as part of the international Seal the Deal campaign.
The campaign aims to push governments towards agreeing a climate change pact at a December summit in Copenhagen, Denmark.
"It would have been a big boost for the issue," he told Rolling Stone.
Asked why his plans had been cancelled, he simply replied: "Money. No sponsors."
Speaking about the anniversary show in March, Mr Lang said he hoped the bill would include some of the acts from the original line-up, including Joe Cocker and Santana.