Over half of this indirect investment in TAP was sold to US risk capital fund Global Aviation Ventures LLC for $30 million. The rest was sold to Brazilian airline Azul.S.A for $25 million, according to the statement.

The HNA Group explained that the business involved the sale of the subsidiary Hainan Airlines Civil Aviation, which has a 20% share in Atlantic Gateway.

Atlantic Gateway owns 45% of TAP. The Portuguese state owns 50% of TAP, with the remaining 5% of capital in the hands of employees.

Azul was founded by Brazilian entrepreneur David Neeleman, who owns 40% of Atlantic Gateway. HNA was at one point a shareholder of Azul but sold this share to institutional U.S investors in August last year.

HNA had less than a month ago bumped its share in Atlantic Gateway from 12% to 20% at a time when it faced liquidity problems.

The Chinese group has recently been selling off investments and cancelling deals, even in the aviation industry - its main business.

One of HNA's subsidiaries - Capital Airlines - in July 2017 launched its first direct flight between China and Portugal, but after a year the company announced it was to be suspended.

HNA, which also detains shares in firms like Hilton Hotels, Swissport or Deutsche Bank, is being supervised by a creditor group led by China Development Bank.