By Sam Nussey and Maki Shiraki

TOKYO (Reuters) - Japan's ANA Holdings Inc <9202.T>, will lease four Boeing <BA.N> 737-800 aircraft while it awaits delayed deliveries of the country's first commercial aircraft in 50 years, the 90-seat Mitsubishi Regional Jet (MRJ), a senior executive told Reuters.

"We have shortages because of the delayed delivery of the MRJ," said Yuji Hirako, who took up the role of president and chief executive of ANA's airline subsidiary, All Nippon Airways Co, on April 1.

ANA, Japan's largest airline, had no plans to cancel its order for 25 of the Japanese-designed jetliners, he added.

The aircraft will be leased from Singapore-based BOC Aviation Limited <2588.HK> and Dublin-based SMBC Aviation Capital, a representative said.

The MRJ, which is being built by a subsidiary of Mitsubishi Heavy Industries <7011.T>, was delayed for two more years in January to redesign its wiring, with first delivery now set for 2020. The latest holdup is the fifth since development began ten years ago.

To tackle the delays, ANA previously said it would push back the retirement of older Boeing 737-500 aircraft and buy three DHC-8-Q400 aircraft from MRJ rival Bombardier <BBDb.TO>. Each of the 737-800s can seat up to twice as many passengers as an MRJ.

(Reporting by Sam Nussey, Makiko Shiraki and Tim Kelly; Editing by Clarence Fernandez)