SINGAPORE, Feb 22 (Reuters) - Airbus faces delays on introducing an ultra-long-range version of its A350-1000 jet designed for Qantas Airways non-stop Sydney-London flights because the regulator has asked it to redesign an extra fuel tank, a senior executive said.

"The regulator has asked us to redesign the centre tank on the ultra-long-range airplane for Sunrise," Christian Scherer, the CEO of Airbus' commercial aircraft business said on Thursday on the sidelines of the Singapore Airshow, referring to the airline's "Project Sunrise" flights from Sydney to London.

Qantas said on Thursday the delivery dates for its first A350-1000 planes capable of the ultra-long-range flights had been pushed back by about six months to mid-2026.

"We have to redesign the centre tank, the extra fuel tank, that will allow the Sunrise mission and that’s what explains the shift," Scherer said. (Reporting by Brenda Goh; Writing by Jamie Freed)