EXHIBIT 2.2 AMENDMENT AGREEMENT This AMENDMENT AGREEMENT is made as of the 1st day of October 1997, by and among Doubletree Acquisition Corp., a Delaware corporation ("Doubletree Sub") and Promus Acquisition Corp., a Delaware corporation ("Promus...

                                                                     EXHIBIT 2.2
 
                              AMENDMENT AGREEMENT
 
    This AMENDMENT AGREEMENT is made as of the 1st day of October 1997, by and
among Doubletree Acquisition Corp., a Delaware corporation ("Doubletree Sub")
and Promus Acquisition Corp., a Delaware corporation ("Promus Sub").
 
    Reference is made to that certain Agreement and Plan of Merger among
Doubletree Corporation, a Delaware corporation ("Doubletree"), Promus Hotel
Corporation, a Delaware corporation ("Promus"), and Parent Holding Corp., a
Delaware corporation, one half of the issued and outstanding capital stock of
which is owned by each of Doubletree and Promus ("Parent") dated as of September
1, 1997 (the "Merger Agreement"). Pursuant to the obligations created by
Sections 1.2 and 1.3 of the Merger Agreement, by this Amendment Agreement
Doubletree Sub and Promus Sub shall hereby become additional parties to the
Merger Agreement and become subject to the provisions thereunder and to the
obligations created thereunder. In addition, by executing this Amendment
Agreement, Doubletree Sub and Promus Sub shall be deemed to have executed and
delivered the Merger Agreement.
 

                                           
DOUBLETREE ACQUISITION CORP.                  PROMUS ACQUISITION CORP.
 
By: /s/Xxxxx X. Xxxxxxx                       By: /s/Xxxxxxx X. Xxxxxxx
   Name: Xxxxx X. Xxxxxxx                        Name: Xxxxxxx X. Xxxxxxx
   Title:  President                             Title:  Chief Executive Officer