NEW YORK (AP) -- Wal-Mart says allegations hushed up bribery by executives in Mexico are "not a reflection of who we are or what we stand for."

The New York Times reports a vast bribery campaign by top executives of its Mexican subsidiary was carried out to build stores across that country.

The newspaper reports that Wal-Mart failed to notify law enforcement officials even after its own investigators found evidence of millions of dollars in bribes. The newspaper said a report by its lead investigator concluded that Mexican and U.S. laws likely were violated.

Wal-Mart is Mexico's largest private employer.

A Wal-Mart spokesman says the company is "deeply concerned" and "working aggressively to determine what happened."

Wal-Mart says its latest, ongoing investigation is being handled by outside lawyers and accountants. The company also said it has tightened procedures and expanded training in Mexico.