partner_print_budget/service_siniestro_fields_view.xml

<?xml version="1.0"?>
<openerp>
    <data>
        <record id="view_service_siniestro_form" model="ir.ui.view">
        <field name="name">project.service.inherit</field>
        <field name="model">project.service.task</field>
        <field name="inherit_id" ref="eiru_service.project_service_task_form"/>
        <field name="arch" type="xml">
         <notebook>
            <page string="Datos de Siniestro" position="before">
                    <group>
                        <group name="siniestro_laboral" col="2" string="Datos de Siniestro">
                            <field name="nro_siniestro"/>
                        </group>
                    </group>
            </page>
         </notebook>
        </field>
        </record>
    </data>
</openerp>