diff --git a/prospect.py b/prospect.py
index ef3d76a..52c95b4 100644
--- a/prospect.py
+++ b/prospect.py
@@ -75,7 +75,19 @@ class AssignOperatorStart(ModelView):
     __name__ = 'sale.prospect.assign.start'
 
     prospects_chunk = fields.Integer('Prospects chunk')
-    operator = fields.Many2One('res.user', 'Operator')
+    operator = fields.Many2One('res.user', 'Operator', required=True)
+    prospects = fields.One2Many(
+        'sale.prospect', None, 'Prospects')
+
+    @fields.depends('prospects_chunk', 'prospects')
+    def on_change_prospects_chunk(self):
+        pool = Pool()
+        Prospect = pool.get('sale.prospect')
+
+        self.prospects = []
+        self.prospects = Prospect.search(
+            [('state', '=', 'unassigned')],
+            limit=self.prospects_chunk)
 
 
 class AssignOperator(Wizard):
@@ -91,14 +103,7 @@ class AssignOperator(Wizard):
     assign = StateTransition()
 
     def transition_assign(self):
-        pool = Pool()
-        Prospect = pool.get('sale.prospect')
-
-        prospects = Prospect.search(
-            [('state', '=', 'unassigned')],
-            limit=self.start.prospects_chunk)
-
-        for prospect in prospects:
+        for prospect in self.start.prospects:
             prospect.assigned_operator = self.start.operator
             prospect.state = 'assigned'
             prospect.save()
diff --git a/tests/scenario_sale_opportunity_management.rst b/tests/scenario_sale_opportunity_management.rst
index de8c06e..4cb1b62 100644
--- a/tests/scenario_sale_opportunity_management.rst
+++ b/tests/scenario_sale_opportunity_management.rst
@@ -91,6 +91,8 @@ Asignar operario a un prospecto::
     >>> assign = Wizard('sale.prospect.assign', [prospect1, prospect2])
     >>> assign.form.prospects_chunk = 2
     >>> assign.form.operator = user
+    >>> assign.form.prospects
+    [proteus.Model.get('sale.prospect')(1), proteus.Model.get('sale.prospect')(2)]
     >>> assign.execute('assign')
 
     >>> prospect1.assigned_operator.name
diff --git a/view/assign_start_form.xml b/view/assign_start_form.xml
index ce83300..857fa8c 100644
--- a/view/assign_start_form.xml
+++ b/view/assign_start_form.xml
@@ -7,4 +7,7 @@ this repository contains the full copyright notices and license terms. -->
     <newline/>
     <label name="operator"/>
     <field name="operator"/>
+    
+    <label name="prospects"/>
+    <field name="prospects"/>
 </form>
\ No newline at end of file