wow I think zen have been too honest 
Pushing prices up because your competitor has done so is a cartel 
NOPE
Cartel noun
1. an international syndicate, combine, or trust formed especially to regulate prices and output in some field of business.
2. a coalition of political or special-interest groups having a common cause, as to encourage the passage of a certain law.
3. a written agreement between belligerents, especially for the exchange of prisoners.
4. a written challenge to a duel.
Pushing prices up because your competitor has done so is reacting to the market.
OR
Pushing prices up because your supplier has done so is changing with your environment.
Various (Dile up) -> clara.net (Dile up) -> TELE2 (Microwave) -> ZeN (ADSL)