ZURICH (Reuters) - A fire has completely destroyed a workshop at Swatch Group's watch mechanism subsidiary, the Swiss watchmaker said on Sunday.

The blaze at ETA Manufacture Horlogere in Grenchen, Switzerland, caused considerable financial damage, Swatch said in a statement without indicating what impact it would have on production.

ETA is the world's biggest supplier of watch "movements", the internal mechanisms that drive the moving parts of a watch, giving Swatch a near-monopoly in these components.

The company statement said it was too early to put a figure on the financial damage and a Swatch spokesman could not immediately be reached for comment.

Swatch, known for its colourful plastic timepieces and high-end Omega brand, said no one was harmed in the fire and the cause of the blaze was unknown.