X0202 4 2007-03-21 0 0000830141 PIONEER COMPANIES INC PONR 0001312908 Gates Capital Management, Inc. 1177 AVENUE OF THE AMERICAS 32ND FLOOR NEW YORK NY 10036 0 0 1 0 0001394281 Gates Capital Partners, L.P. 1177 AVENUE OF THE AMERICAS 32ND FLOOR NEW YORK NY 10036 0 0 1 0 0001361105 ECF VALUE FUND L P 1177 AVENUE OF THE AMERICAS 32ND FLOOR NEW YORK NY 10036 0 0 1 0 0001270166 ECF VALUE FUND II LP 1177 AVENUE OF THE AMERICAS 32ND FLOOR NEW YORK NY 10036 0 0 1 0 0001221469 ECF VALUE FUND INTERNATIONAL LTD 1177 AVENUE OF THE AMERICAS 32ND FLOOR NEW YORK NY 10036 0 0 1 0 Common Stock 2007-03-21 4 P 0 100000 27.8928 A 1721208 I Investment Manager, see remarks below See remarks field. Gates Capital Management, Inc., which is controlled by Jeffrey L. Gates, is the general partner of Gates Capital Partners, L.P., which is the general partner of ECF Value Fund, L.P. and ECF Value Fund II, L.P. and thereby is solely responsible for the trading and investment decisions of ECF Value Fund, L.P. and ECF Value Fund II, L.P. Gates Capital Management, Inc. is also the investment manager of ECF Value Fund International, Ltd. and thereby is solely responsible for the trading and investment decisions of ECF Value Fund International, Ltd. The following persons shall be considered to be Reporting Persons for purposes of this Form: Gates Capital Management, Inc., Gates Capital Partners, L.P., Jeffrey L. Gates, ECF Value Fund, L.P., ECF Value Fund II, L.P. and ECF Value Fund International, Ltd. For purposes of this Form, the securities reported herein are deemed to be beneficially owned collectively by the Reporting Persons. Gates Capital Management, Inc. Gates Capital Partners, L.P. Jeffrey L. Gates ECF Value Fund, L.P. ECF Value Fund II, L.P. ECF Value Fund International Ltd. By: Jeffrey L. Gates, President, Gates Capital Management, Inc., an authorized person 2007-03-23