If it is your company name, a tradename or trademark, and the other company cannot claim any legal rights to the name it registered, you should appeal to the Alternative Dispute Procedure. This is a fast procedure that typically takes about 50 days between the submission of the complaint and the decision of the mediator. More information about the ADR Procedure can be found under Domain Name Info/Disputes.
These disputes can be treated by traditional courts as well.
In all other cases (e.g. generic names), nothing can be done since this is a "first come, first served" system.
