DUBLIN - The executive chairman of aircraft leasing firm Air Lease Steven Udvar-Hazy on Monday said he was hopeful that Boeing's grounded 737 MAX would be cleared to fly by regulators within 90 days, but that issues continued to mount for the jet.

"It is still not clear when FAA/EASA will sign off the aircraft. We are hoping its going to happen in the next 90 days," Udvar-Hazy told the Airline Economics annual aviation finance conference in Dublin, referring to U.S. and European regulators.

"But it almost feels like every week there are new developments that cause us to be concerned about the timeliness of the return to service of the 737 MAX," he said.

(Reporting by Conor Humphries) ((conor.humphries@thomsonreuters.com; +35315001518; Reuters Messaging: conor.humphries.thomsonreuters.com@reuters.net))