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China Southern Airlines wants U.S. firms to speak out against protectionism -chairman

* State carrier's chairman opposes U.S. stance on trade

* Says carrier firmly advocates China's response

* To add 115 planes to fleet by 2018-end (Recasts with chairman's comments, adds trade war context)

HONG KONG, March 27 (Reuters) - China Southern Airlines Co Ltd's chairman on Tuesday said the carrier "strongly opposes" what he called the United States' protectionist stance on trade with China, and hopes U.S. firms relay to Washington that protectionism will be detrimental to both sides.

Wang Changshun made the comments at an earnings briefing held a day after the state-owned carrier, China's largest by passenger numbers, reported a 17 percent jump in annual profit.

Tensions between the U.S. and China flared last week after Washington announced plans for tariffs on up to $60 billion worth of Chinese goods, with Beijing following with its own tariff plans. Global markets tumbled but concerns have since eased with reports of the sides negotiating.

"This kind of (U.S.) policy does not benefit people in China or the U.S., or the healthy development of enterprises in both countries," Wang said. "We firmly advocate any decision the Chinese government makes and hope U.S. companies can make suggestions to their government."

Wang did not comment directly on how any potential trade war could impact China Southern's business. The carrier counts among its investors American Airlines Group Inc, which paid $200 million for a stake last year and with which it now has a code-sharing partnership.

Also at the briefing, Chief Financial Officer Xiao Lixin said China Southern will take delivery of 115 aeroplanes in 2018, taking its fleet to 840 aircraft by the end of the year.

Of those 115 planes, 71 will be from Boeing Co and the remainder from Airbus SE, showed China Southern's annual report. The report also showed the airline will retire 29 aircraft this year, and that its fleet will reach 979 planes by 2020.

China Southern on Monday booked record profit for 2017 due to robust travel demand and a strengthening yuan, albeit capped by higher-than-expected operating costs.

(Reporting by Tina Ge in HONG KONG; Writing by Brenda Goh in SHANGHAI; Editing by Christopher Cushing)