A spac transaction and a spac ship have been disputed by eBay over the payment method, with PayPal and eBay insisting they are still in talks.
The dispute arose in July last year, when PayPal and the UK’s National Space Centre said they would stop accepting payments from the US space agency.
Ebay refused, arguing that PayPal had agreed to pay the £5.9m for the Spaceport America project.
But a spokeswoman for eBay said the company was still in negotiations with PayPal.
“We continue to negotiate with PayPal over the Spaceports deal,” she said.
“This is the first time that we have ever made such a proposal to eBay in relation to a PayPal transaction, and we are not in any way prepared to stop negotiations at this time.”
PayPal said it was still looking for the UK space agency to provide more information about how the company would use the funding to pay for the project.
A spokesman for eBay declined to comment.
PayPal has been negotiating with the British government for more than a year, after the US rejected a $1.9bn (£1.25bn) deal with the UK government.
The US space station programme is in its 14th year and was started by the American astronaut Buzz Aldrin in 2004.
It has now expanded to include a third space station, and has helped develop and launch satellites and probes to study the universe.
But the US Congress has been critical of the space agency, accusing it of lacking the ability to safely and reliably send astronauts to the ISS, and of being too close to its own country.
The spaceport is part of the Nasa space station complex, which is owned by the US government.
A Nasa spokesman said: “This is not about politics.
This is about doing business.”