Kingboard Chemical Holdings said the Hong Kong-listed company and its subsidiaries entered an agreement on Sunday to sell their shares in Cathay Pacific Airways to Qatar Airways for HK$5.16 billion ($662 million) in cash.
Elsewhere in Asia, Qatar Airways is looking to establish a division in India that could operate as many as 100 single-aisle planes as Qatar's flagbearer seeks to tap into the world's fastest growing major aviation market.
Qatar's flag carrier had earlier announced an agreement to purchase 378,188,000 shares in Cathay Pacific Airways Limited, equivalent to approximately 9.6% of the total issued share capital, from Hong Kong-based Kingboard Chemical Holdings.
Doha-based Qatar Airways has taken a 6.9% stake in Cathay Pacific.
CEO Akbar Al Baker described Cathay as "one of the strongest airlines in the world, respected throughout the industry and with massive potential for the future".
Chief executive for Cathay Pacific, Rupert Hogg said that "As members of the Oneworld airline alliance, we look forward to a continued constructive relationship".
"Cathay will have three major shareholders, all with different and potentially conflicting interests - Swire, Air China and Qatar Airways", said Corrine Png, CEO of transport research firm Crucial Perspective. "This may not necessarily be favorable for Cathay as it is facing operating challenges and undergoing transformation".
Swire Pacific owns 45% of Cathay and Air China 30%.
Qatar Airways has been trying to compensate for this lost traffic and revenue by increasingly looking at global markets to expand its reach.
Kingboard Chemical said the group, which will cease to hold any Cathay Pacific shares following the transaction, will recognize a gain of about HK$800 million from the sale in its annual results.
At the same time, Cathay, while still Asia's biggest worldwide airline, has struggled to make the most of its Chinese status, finding itself squeezed by mainland carriers that boast a lower cost base and increasingly offer direct USA and European flights, cutting out the need for people to go via Hong Kong.
In other Qatar Airways-related news, The Times of India reported that a Qatar Airways Doha-Bali flight was diverted to Chennai after an "intoxicated" Iranian woman used her sleeping husband's thumb to open his mobile phone - and discovered messages that she believed showed he was cheating on her.