Seagate has expanded its battle against fellow hard disk drive maker Cornice by taking its patent infringement claims to the US International Trade Commission (ITC).

In its latest complaint, Seagate is asking the ITC to block import to the US of any products containing Cornice drives, said Woody Monroy, a spokesman for Seagate. Last month, Seagate filed a patent infringement suit against Cornice which asked the court to prevent Cornice from selling its drives in the US, as well as unspecified damages.

Cornice makes one-inch hard-disk drives branded "Storage Element" that are used in a number of portable electronics devices including MP3 players from Sony, Digital Networks, iRiver and Digitalway. Cornice is a tiny company in comparison to Seagate but its memory technology provides four times the capacity of other one-inch drives at the same price.

Seagate is looking to expand into the booming one-inch market. And its efforts at stifling Cornice have been backed up by competitor Western Digital, which also filed a patent infringement suit against Cornice last week.