JOINDER AGREEMENT

Exhibit 4.3

JOINDER AGREEMENT

The undersigned hereby agrees, effective as of the date hereof, to become a party to that certain Investor Rights Agreement, dated as of February 9, 2006, by and among AECOM Technology Corporation (the “Company”) and the parties named therein, as amended by that certain Amendment No. 1 to the Investor Rights Agreement, dated as of February 14, 2006, by and among the Company and the parties named therein (collectively, the “Agreement”), and for all purposes of the Agreement, the undersigned shall be included within the term “Investor” (as defined in the Agreement).  As of the date hereof the undersigned represents and warrants that X.X. Xxxxxxx VI, L.P. is a Delaware limited partnership, the sole general partner of which is X.X. Xxxxxxx Equity Partners VI, LLC, a Delaware limited liability company, the managing members of which are each a natural person who is a citizen of the United States.  For purposes of clarification, X.X. Xxxxxxx VI, L.P. constitutes an “Investor” for purposes of, and as defined in, the Agreement.  The address and facsimile number to which notices may be sent to the undersigned is as follows:

	Address:
	X.X. Xxxxxxx VI, L.P.
	000 Xxxxx Xxxxxx
	Xxxxxxxx, XX 00000
	Attention: Xxxxx X. Xxxxxx
	Facsimile No.:
	(000) 000-0000
	with a copy to:
	Xxxxxx, Xxxx & Xxxxxxxx LLP
	0000 Xxxxxxx Xxxx Xxxx, Xxxxx 0000
	Xxx Xxxxxxx, XX 00000
	Attention: Xxxxxxxx Xxxxx
		X.X. Xxxxxxx VI, L.P.
		By:		X.X. Xxxxxxx Equity Partners VI, LLC
		Its:		General Partner
		By:
			Name: Xxxxxxx X. Xxxxxxxx
			Title: Managing Member

Whitney Joinder Agreement to Investor Rights Agreement

Acknowledged and agreed to by:

AECOM Technology Corporation

By:

Name:

Title: