queueClient.OnMessageAsync(message=>
                      Task.Factory.StartNew(new Action(()=> ProcessMessage(message))));

static void ProcessMessage(BrokeredMessage message)
    {
        Trace.WriteLine("Procesing Service Bus message nº::" + message.SequenceNumber.ToString());
    }

queueClient.OnMessageAsync(message=>  ProcessMessage(message));
    }

    static async Task  ProcessMessage(BrokeredMessage message)
    {
        Trace.WriteLine("Procesing Service Bus message nº::" + message.SequenceNumber.ToString());

    }