Asia's largest carrier has moved to restore its financial health by slashing thousands of jobs, scrapping unprofitable routes and stepping up lucrative business class services.

"Downsizing efforts have paid off," Yoshimasa Kanayama, an executive board member of the company, told a news conference.

"Even though the JAL Group has made great strides towards achieving its overriding goal of building a robust management framework, a business structure which can produce profits even in the face of factors such as rising fuel costs or slowing demand, the business environment continues to be severe," a JAL statement warned.