Relational Investors SC 13D L 3 COMMUNICATIONS / RELATIONAL INVESTORS ownership change

Exhibit 99.B

Exhibit B

JOINT FILING AGREEMENT

In accordance with Rule 13d-l(k) under the Securities Exchange Act of 1934, as amended, the persons named below agree to the joint filing on behalf of each of them of a statement on Schedule 13D (including amendments thereto) with respect to the common stock, $.01 par value, of L-3 Communications Holdings, Inc. and further agree that this Joint Filing Agreement be included as an Exhibit to such joint filing.  In evidence thereof, the undersigned hereby execute this Agreement this 22nd day of June, 2011.

RELATIONAL INVESTORS, L.P.
RELATIONAL FUND PARTNERS, L.P.
RELATIONAL COAST PARTNERS, L.P.
RH FUND 1, L.P.
RH FUND 6, L.P.
RELATIONAL INVESTORS VIII, L.P.
RELATIONAL INVESTORS IX, L.P.
RELATIONAL INVESTORS X, L.P.
RELATIONAL INVESTORS XV, L.P.
RELATIONAL INVESTORS XVI, L.P.
RELATIONAL INVESTORS XX, L.P.
RELATIONAL INVESTORS XXII, L.P.
RELATIONAL INVESTORS XXIII, L.P.
RELATIONAL INVESTORS ALPHA FUND I, L.P.

By:	RELATIONAL INVESTORS, LLC
	as general partner to each, except as the sole managing member of the general partners of Relational Alpha Fund I, L.P. and Relational Investors X, L.P.

	By:	/s/ Ralph V. Whitworth
		Ralph V. Whitworth, Principal
RELATIONAL INVESTORS, LLC
	By:	/s/ Ralph V. Whitworth
		Ralph V. Whitworth, Principal
/s/ Ralph V. Whitworth
Ralph V. Whitworth
/s/ David H. Batchelder
David H. Batchelder