July 22 (Reuters) - China will extend anti-dumping duties on grain oriented flat-rolled electrical steel imported from Japan, South Korea, and the European Union, the country's ministry of commerce said on Friday.

The duties will be extended for five years beginning from July 23, it said in a statement.

The anti-dumping duty rates are set at 39% to 45.7% for Japanese firms including JFE Steel Corp and Nippon Steel Corp, 37.3% for Korean companies and 46.3% for EU firms.

China, the world's top steel producer launched an anti-dumping investigation in June last year into grain oriented flat-rolled electrical steel from Japan, South Korea and the EU following the expiry of tariffs in place for the past five years.

The tariffs were reinstated during the year-long investigation.

The move followed a petition by steelmakers China Baoshan Iron and Steel and a unit of Beijing Shougang which argued that ending the tariffs could lead to further dumping, hurting the domestic steel sector.

Oriented electrical steel or oriented silicon steel is used in transformers and is more expensive than carbon steel.

(Reporting by Emily Chow in Kuala Lumpur; Editing by Richard Pullin)