Phelps Dodge 10-Q 2006 Q3 Quarterly report

Exhibit 15

Securities and Exchange Commission
100 F Street, N.E.
Washington, DC 20549

Commissioners:

We are aware that our report dated October 23, 2006 on our review of interim financial information of Phelps Dodge Corporation for the three-month and nine-month periods ended September 30, 2006 and 2005 and included in the Company’s quarterly report on Form 10-Q for the quarter ended September 30, 2006 is incorporated by reference in its Registration Statement on Form S-3 (No. 333-124094), the Registration Statements on Form S-8 (Nos. 33-26442, 33-6141, 33-26443, 33-34362, 33-62648, 333-117382, 333-42231 and 333-52175), and Post-Effective Amendment No. 4 on Form S-8 to the Registration Statement on Form S-4 (No. 333-86061).

Very truly yours,

/s/ PricewaterhouseCoopers LLP
Phoenix, Arizona
October 23, 2006