An Airbus A330 jet plane of Hainan Airlines of HNA Group takes off from the Shenzhen Baoan International Airport in Shenzhen city, South China's Guangdong province, December 30, 2014. [Photo/IC]

Hainan Airlines is set to launch its first direct flight route between China and London, with a new non-stop service linking the UK capital and Changsha in Hunan province.

The Chinese carrier said, starting on March 23, three of its Boeing 787 passenger jets will depart each week from Changsha Huanghua International Airport and arrive at London's Heathrow Airport before making the return journey.

Flights will depart from Changsha in the morning, just before noon, and arrive in London mid-afternoon on the same day. The return flights leave Heathrow late at night and arrive in Changsha the next day, in the middle of the afternoon.

The new route is Hainan Airline's second direct link between the UK and China. The carrier started flying a non-stop route between Beijing and Manchester, in Northern England, in June last year.

Since then, exports from Northern England to China have almost tripled, to 200 million pounds ($270 million) a month, and the amount spent by Chinese tourists in Manchester has doubled to 138 million pounds a year, according to a report by the Manchester China Forum and Manchester Airport.

International carriers operate around 60 flights a week between the UK and China.

In December, the UK and China agreed to raise the limit on the number of direct weekly flights between the two nations to 150, from 100.

Hainan Airlines said the new route will provide a link between the British capital and one of China's most "famous historical cities".

"Changsha is the political, economic, cultural, and technological hub of Hunan province," the airline said in a statement.

The UK's Department for International Trade has previously promoted Changsha as a business destination among British engineering companies. The city has a strong cluster of advanced engineering businesses, among them some of the largest manufacturers of construction machinery in China.

Hainan Airlines is China's fourth-largest and has rapidly grown its long-haul network in recent years to connect several major international airports with hubs in Chengdu, Chongqing, Shenzhen, and Changsha.

The new London route joins three other long-haul routes that will get off the ground in March, including new Brussels and Madrid links with Shenzhen and a route between Beijing and Tijuana in Mexico.

The announcement of the new route comes as the owner of Hainan Airlines, Chinese conglomerate HNA Group, looks to offload assets amid liquidity concerns.

HNA is seeking buyers for its stake in the NH Hotel Group, a Spain-based company that operates 400 hotels in more than 30 countries. HNA has a 29.5 percent share in the hotel chain, valued at $770 million.

Lin Zhijie, an aviation industry analyst and columnist at one of China's largest civil aviation web portals Carnoc, said that the sale was precipitated by new financial policies outlined by the Chinese government.

"The government has adjusted its policies over the supervision of overseas investments, and the lending rates at banks have been higher," Lin said in a previous interview. "In the past few years, HNA has been a bit aggressive in its overseas mergers and acquisitions, and it is facing financial difficulties due to stricter controls."