By issuing a proposal, representing an invitation to negotiate, the issuer does not lose the right to refuse initiation and realization of negotiations. But this right can not be exercised discretion because he, in this situation, acquires certain limits that you do not have the refusal to contract. What will be the legal value of an invitation to negotiate? We believe that it is producing legal effects revealed by the tort liability if unjustified refusal to enter into negotiations. By issuing this invitation he created a trusted party or parties to whom it is intended, trust that he is cheating refusing initiation of negotiations and hence the possibility of concluding the contract design. He allowed himself to believe that anyone can pick up option in treating conditions that are customary in such deals. However this does not mean that the issuer negotiating proposal shall refuse to negotiate. Then, when economic considerations require it could invoke this right since it was justified (refusal).