BEIJING (Reuters) - Chinese aircraft lessor Bohai Capital (>> Bohai Financial Investment Holdng Co Ltd), known for its September purchase of Irish peer Avolon Holdings Ltd, aims to nearly double its fleet in coming years to take advantage of a boom in Chinese travel demand, a top executive told Reuters.

Bohai Capital and other state-backed firms are expanding in the aircraft financing and leasing business as customer airlines open routes at home and abroad. China's outbound leisure travellers topped 100 million in 2014, with the number set to grow 10 percent this year, according to official figures.

Bohai Capital, the leasing arm of aviation-to-shipping conglomerate HNA Group, plans to add 300 to 400 planes to the over 500 it has on order and in service, Chief Operating Officer Ren Weidong told Reuters in an interview this week.

"Aviation remains the top priority for us because of the huge growth potential, especially in China and Asia-Pacific," Ren said. "Airports in Beijing or Shanghai are packed, but there are hardly any planes in many small cities in mid- and western regions."

Bohai Capital, based in the northwest province of Xinjiang, is betting that the Avolon purchase would help it break into the aircraft leasing industry's top three, alongside AerCap Holdings NV (>> AerCap Holdings N.V.) and General Electric Co's (>> General Electric Company) GECAS.

Its major customers include HNA Group and affiliates. Group companies include Hainan Airlines Co Ltd (>> Hainan Airlines Co., Ltd.), budget carrier West Air and a dozen or so other carriers. The group also owns 9 airports.

Shares of the company, formally known as Bohai Financial Investment Holding Co Ltd, have been suspended since January ahead of another possible acquisition.

Ren declined to comment on the target, but said listed firms are required to suspend trading of their shares if the size of any deal exceeds 50 percent of net assets.

Bohai Capital, Asia's biggest aircraft lessor by assets, had net assets of nearly 11 billion yuan (1 billion pounds) at the end of September, its latest exchange filing showed.

Ren also said commercial aviation revenue should continue to grow at twice the rate of economic expansion, or about 15 percent this year.

Bohai Capital is also the world's largest container leasing service provider, following last year's purchase of Cronos Ltd.

"We are a tier-one player now. We are affected by the downturn but not as much as other companies," he said. "The merger will help to keep our costs down."

(Reporting by Fang Yan and Matthew Miller; Editing by Denny Thomas and Christopher Cushing)

By Fang Yan and Matthew Miller