SEOUL (Reuters) - South Korea on Thursday condemned as "historic distortion" an effort by Japan to register 19th century industrial facilities as UN world heritage sites, urging full disclosure of Japan's use of Korean forced labour at some of them.

Japan's move to list the 23 industrial sites, many of them coal mines, shipyards and steel mills dating back to 1850, in a Unesco programme, has stoked anger in South Korea as another attempt to gloss over Japan's colonial and wartime past.

"Space and time continue. Japan is unable to deny (forced labour) existed, so it is trying to avoid it," a South Korean foreign ministry official told a small group of Western media. "It can possibly turn into another case of historic distortion," the official said, speaking on condition of anonymity because of the sensitivity of the subject.

Japan's bid, and South Korea's objection, are likely to further fuel diplomatic tension between the Asian neighbours, centred on issues stemming from Japan's colonial rule of the Korean peninsula between 1910 and 1945.

South Korea's ties with Japan have long been marred by what Seoul sees as Japanese leaders' reluctance to atone for the country's wartime past, including a full recognition of its role in the sexual slavery of Korean women at military brothels.

The neighbours are also embroiled in a territorial dispute over islands that lie between them.

South Korea's foreign ministry said seven of the 23 sites were run as forced labour camps, employing about 57,900 Koreans during Japan's colonisation of Korea, and 94 workers died there.

Japan sees the sites as evidence of its industrial modernisation, and has said the Unesco listing relates to their use in the period before World War Two.

On Monday, Japan said Unesco's advisory panel had backed the application, recommending enlistment of the sites as world heritage locations at a June session of the UN cultural body.

South Korean officials plan to meet Japanese officials this month to try and negotiate revisions to Tokyo's Unesco application, the ministry said.

The ministry official added that Japan should drop from its application seven sites that employed Korean forced labour, or consider a listing along the lines of the German Nazi concentration and death camp of Auschwitz-Birkenau, already included on the Unesco list.

Japanese courts have thrown out claims by South Koreans forced by Japan to work as slave labourers, saying the matter of compensation was closed under a 1965 treaty between the two countries that established diplomatic ties.