Form: SC 13D/A

Schedule filed to report acquisition of beneficial ownership of 5% or more of a class of equity securities

March 2, 2004

JOINT FILING AGREEMENT OF SCHEDULE 13D

Published on March 2, 2004

EXHIBIT A
JOINT FILING AGREEMENT

We, the signatories of the statement on Schedule 13D filed with respect
to the Common Stock of Quanta Services, Inc., to which this Agreement is
attached, hereby agree that such statement is, and any amendments thereto filed
by any of us will be, filed on behalf of each of us pursuant to and in
accordance with the provisions of Rule 13d-1(k) of the Securities Exchange Act
of 1934.

Dated: March 2, 2004


FIRST RESERVE FUND IX, L.P.

By: First Reserve GP IX, L.P.,
General Partner
By: First Reserve GP IX, Inc.,
General Partner


By: /s/ THOMAS R. DENISON
------------------------------------
Name: Thomas R. Denison
Title: Managing Director



FIRST RESERVE GP IX, L.P.

By: First Reserve GP IX, Inc.,
General Partner


By: /s/ THOMAS R. DENISON
------------------------------------
Name: Thomas R. Denison
Title: Managing Director



FIRST RESERVE GP IX, INC.


By: /s/ THOMAS R. DENISON
------------------------------------
Name: Thomas R. Denison
Title: Managing Director