After the notice of intention to enter judgment required by Rule 237.1 has been given, the parties may agree in writing to extend the time within which to file a complaint, an answer or preliminary objections. The agreement shall be in the form prescribed by Rule 237.6 and shall be signed on behalf of both parties. If the required action is not taken within the time specified in the agreement, judgment of non pros or by default may be entered by the prothonotary without further notice under Rule 237.1.