Thai Airways International PCL (THAI.TH) said Wednesday the natural disasters in Japan have hurt its revenue by around THB600 million ($20 million) following a drop in traffic.

The cabin factor on the Bangkok-Japan routes has fallen by 7.4 percentage points to 73% from a year ago, President Piyasvasti Amranand told reporters.

However, he added that traffic on other routes including China, Singapore and Hong Kong has increased during that time.

The national carrier plans to reduce the flight frequency to Japan, adding more services for the Bangkok-Hong Kong route and apply larger planes for China routes, Piyasvasti said.

Separately, he said the board Wednesday approved a plan to lease two Boeing 777-300 ER aircraft from Jet Airways (India) Ltd. (532617.BY) for two years.

The leased planes are expected to be delivered to Thai Airways in October and November. The leasing fee is around $1.5 million a month.

Also, Thai Airways' board has agreed to hire Boeing (BA) to convert its two old B747-400 passenger planes into freighters for $49.5 million. The delivery is expected in March and April next year.

-By Bangkok Bureau; Dow Jones Newswires; 66 2 690 4200; djnews.bangkok@dowjones.com