Agent isn't marketing as they said they would can you break contract, and list elsewhere?

Silverdragon - A contract is an agreement between two parties.  If you feel as though your agent is not up holding their end of the baragin, then you have cause to cancel the contract.  HOWEVER, with that being said...my suggestions would be to speak with that agent and clarify what you thought their duties were. 

Depending on the type of listing agreement you signed, most state that they will market your property within the MLS and other areas.  If you do not have a specific written guideline of where your agent was going to market your property then you have the unwritten contract of what you thought should be done.  My mother always said you can't get mad at the unwritten contract.

I would give the agent the opportunity to hear you out first, as they may have had different expectations than you.  If after this, you feel as though they are not working for you in the manner you see fit, contact another agent after you cancel the contract.  BUT...beware your contract may have some stipulations about early cancelation fees.

Good luck with your sale.
Natalie

Your agent isn't fulfilling their agreement with you and you should replace them with someone who will.  In this market, your agent has to find the buyer in order to sell your house in a timely manner.