* Lotte International board approves THAAD land swap - ministry
* S.Korea, U.S. aim to deploy THAAD in this year
* China opposes THAAD in South Korea, warned Lotte of consequences (Updates with comment from ministry and Chinese foreign ministry, background)
SEOUL, Feb 27 (Reuters) - The board of an affiliate of South Korea's Lotte Group approved a land swap with the government on Monday that will enable authorities to deploy a controversial U.S. missile defence system, the defence ministry said.
The government decided last year to deploy the U.S. Terminal High Altitude Area Defence (THAAD) system in response to the North Korean missile threat, on land that is part of a golf course owned by Lotte in the Seongju region, southeast of Seoul.
The board of unlisted Lotte International Co Ltd approved the deal with the government, and the ministry and Lotte were due to sign an agreement as early as Tuesday, the ministry said.
Lotte could not be immediately reached for comment.
South Korea has said it and the United States aim to make the system operational by the end of the year. A South Korean military official said last week the deployment could be completed by August.
But China objects to the deployment in South Korea of the THAAD, which has a powerful radar capable of penetrating Chinese territory.
Chinese Foreign Ministry spokesman Geng Shuang repeated China's opposition it on Monday, saying it would not help peace and stability of the Korean peninsula, and called on South Korea and the United States not go to go ahead.
China will take necessary steps to protect its security interests, Geng said, without giving details.
"All the consequences of that are the responsibility of South Korea and the United States," he told a daily news briefing in Beijing.
Chinese state media recently warned the Lotte Group, South Korea's fifth-largest conglomerate, that it would face severe consequences if it allowed its land to be used for the missile system.
The Lotte Group said on Feb. 8 Chinese authorities had stopped construction at a multi-billion dollar real estate project in China after a fire inspection, adding to concern in South Korea about damage to commercial relations with the world's second-largest economy.
South Korea's central bank said this month the number of Chinese tourists visiting the tourist island of Jeju had fallen 6.7 percent over the Lunar New Year holiday from last year, partly because of China's "anti-South Korea measures due to the THAAD deployment decision".
Earlier, South Korean officials said they suspected a Chinese decision in December to deny applications from South Korean airlines to expand charter flights was "indirect" retaliation for deployment of the missile system.
But Finance Minister Yoo Il-ho later said China had not taken any retaliatory measures over the missile system that merited official response, though adding South Korea was ready to complain about any "unfair" action. (Reporting by Ju-min Park and Joyce Lee; Additional reporting by Ben Blanchard in Beijing; Writing by Se Young Lee; Editing by Robert Birsel)