China's Ministry of Commerce (MOC) said Tuesday that it would impose temporary anti-dumping measures on terephthalic acid imported from Thailand and the Republic of Korea (ROK).

The preliminary ruling required importers of terephthalic acid from Thailand and the ROK to place deposits starting Wednesday, said a statement on the MOC website.

The statement said companies from those two countries had dumped terephthalic acid on the Chinese market, caused substantial damage to China's domestic industry.

The statement also listed deposit rates for products imported from the ROK at 2.4 percent to 11.2 percent and for products from Thailand 12.2 percent to 20.1 percent.

In another brief statement, the MOC said it would prolong anti-dumping investigation into terephthalic acid from Thailand and the ROK for six months until Aug. 12.

The decision was made because "the situation in this case is quite special and complicated," said the statement without giving further details.

The MOC started an anti-dumping probe into terephthalic acid from Thailand and the ROK on Feb. 12, 2009. The MOC said in a statement last February that the investigation would normally be finished within a year, but might last until Aug. 12, 2010.

Terephthalic acid is an organic compound used in polyester coatings and resins.