Websphere returns 400 error code when special characters are used

Issue

Websphere returns http 400 error due to a special char during a start process command call.

Here is an example of such call:

<command-request>
    <deployment-id>sampleDeploymentId</deployment-id>
    <ver>6.2.0.1</ver>
    <start-process processId="sampleProcessId">
        <parameter>
            <item key="RelationshipManagement">
                <value xsi:type="relationshipManagementDto" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
                    <relationshipManagementType>
                        <code>01</code>
                        <label>Entrée en Relation</label>
                    </relationshipManagementType>
                    <attributesMap>
                        <entry>
                            <key>firstMode</key>
                            <value>OPENING</value>
                        </entry>
                    </attributesMap>
                </value>
            </item>

        </parameter>
    </start-process>
</command-request>

If é is replaced with e then the request is processed without any errors.