In multiagent systems, a cooperative action requires a mutual agreement among multiple agents and the agreement is generally reached by exchanging messages between them, but the delay of message may cause the delay of agreement, and the delay of agreement may reduce the effect of the cooperative action. A speculative action is an action that is taken before agreement not to reduce the effect of cooperative action, but it has to be cancelled by paying a penalty if the agents do not reach an agreement. In this framework, we have two risks; a risk to reduce the effect of cooperative action and a risk to cancel the speculative action, and need risk management methods. In this paper, we propose two risk management methods called the hybrid method and the leveled method, which are viewed as a single agent approach and a multiagent approach respectively, and discuss their advantages using a meeting room reservation problem.