(Corrects spelling of Eastar in second paragraph)
SHANGHAI, March 10 (Reuters) - Airline operators cut some routes between China and South Korea as the fallout spread on Friday from a diplomatic row over Seoul's plans to deploy a U.S. missile defense system regardless of Beijing's objections.
In a statement on its website Korea's Eastar Jet Inc said it was stopping flights between the South Korean cities of Cheongju and the tourist hotspot Jeju with various Chinese cities including Ningbo, Jinjiang and Harbin.
This followed Carnival Corp's Costa Cruises and Royal Caribbean Cruises Ltd cancelling South Korean port visits by their China-based cruises. Royal Caribbean cited "recent developments regarding the situation in South Korea".
A South Korean government document seen by Reuters said China recently gave a "7-point" verbal instruction to travel firms to curtail or ban trips to South Korea.
The crackdown has sent a chill across South Korea's retail and tourism sectors, which rely heavily on China trade, and prompted South Korea to say it will consider filing a complaint against China to the World Trade Organization over what it described as trade retaliation over the THAAD deployment issue.
According to searches of their websites on Friday, China Eastern Airlines Corp Ltd and Spring Airline Co Ltd have stopped selling tickets for mid-next week onwards for flights between the eastern Chinese city of Ningbo and popular South Korean tourist island Jeju.
The two airlines did not respond to requests for comment.
Princess Cruises, also owned by Carnival, said in a statement to Reuters on Friday it would changes its routes to remove visits to South Korea, which it said would give passengers more time on the boat and at Japanese sites.
"Due to the current situation, Princess Cruises' China team has been in close dialogue and prudent discussions with relevant departments," the firm said. "All routes which involve South Korea have been altered."
South Korea relies heavily on Chinese tourists, who make up nearly half of all foreign visitors, official Korean data show.
Reporting by Adam Jourdan and Muyu Xu in BEIJING