X0202 5 2005-12-31 0 0 1 0001298341 Nalco Holding CO NLC 0001306161 HARKER DANIEL M 1601 WEST DIEHL ROAD NAPERVILLE IL 60563-1198 0 1 0 0 Sen. VP, Supply Chain & eCom Common Stock 2005-12-22 4 X 0 L 125679 A 125679 D Exchange Right (right to buy) 2005-12-22 4 X 0 L 66000000 D Common Stock 125679 144000000 D On December 22, 2005, pursuant to the exchange rights of such units, the Reporting Person transferred the following membership units of Nalco LLC (the direct parent company of Nalco Holding Company) in exchange for shares of Nalco Holding Company common stock owned by Nalco LLC: all of his previously reported 30,000,000 class A units, 13,500,000 vested units of his previously reported class B units, 13,500,000 vested units of his previously reported class C units and 9,000,000 vested units of his previously reported class D units. Class A units are exchangeable at a ratio of 448.117 units for each share of Nalco Holding Company common stock; class B units are exchangeable at a ratio of 599.365 units for each share of Nalco Holding Company common stock; class C units are exchangeable at a ratio of 601.528 units for each share of Nalco Holding Company common stock; and class D units are exchangeable at a ratio of 653.841 units for each share of Nalco Holding Company common stock. The Reporting Person has the right to transfer his Nalco LLC class A units, along with those of his class B, class C and class D units that have vested, in exchange for shares of Nalco Holding Company common stock owned by Nalco LLC. Class A units are unconditional; class B units, class C units and class D units will vest for continuing employees at certain dates and are subject to earlier vesting in some circumstances based upon reaching certain performance requirements as described in the Management Members Agreements, which are filed as Exhibits 10.30 to 10.39 to the Registration Statement on Form S-1 of Nalco Holding Company (File No. 333-118583) (the "Management Members Agreements"). These rights to exchange Nalco LLC units for Nalco Holding Company common stock are exercisable following the date that is the later of the date on which any applicable lock-up period pursuant to the initial public offering of Nalco Holding Company terminates and the date that is six months and one day after (i) June 30, 2004 (in the case of class A units) or (ii) the date on which the class B, class C and class D units vest. Class B units will vest in five equal annual investments on each December 31, beginning on December 31, 2004, subject to certain restrictions. Class C units will vest on the 8th anniversary of the date on which they are sold to a manager, subject to certain restrictions, but may vest earlier over the next five years, beginning on December 31, 2004, if Nalco Holding Company meets certain EBITDA targets. Class D units will vest on the 10th anniversary of the date on which they are sold to a manager, subject to certain restrictions, but may vest earlier over the next five years, beginning on December 31, 2004, if Nalco Holding Company meets certain EBITDA targets. See the Management Members Agrements. Subject to the exercise of a call right, for so long as certain termination events (see the Management Members Agreements) have not occurred with respect to the Reporting Person, there is no expiration of the right to exchange Nalco LLC units for Nalco Holding Company common stock. Not applicable. Following the reported transaction, the Reporting Person owns 54,000,000 class B units, 54,000,000 class C units and 36,000,000 class D units of Nalco LLC, which have the exchange rights described herein. /s/ Filomena Trombino as Attorney in Fact 2006-01-12