CINCINNATI — Procter & Gamble Co., a huge consumer products maker whose products include Crest toothpaste and Pampers diapers, is suing the U.S. government for nearly $435 million.

The Cincinnati-based company says the government owes it that amount in taxes and interest after it was "erroneously and illegally assessed" in an IRS audit. The IRS had billed P&G in June after an audit of returns for its 2001-2005 tax years, the lawsuit states.

P&G says it paid the additional taxes and interest the IRS claimed were owed, but is suing to get the money back.

The dispute stems over credits and deductions for technologies donated to universities, medical centers and research foundations; donated artwork, costs of obtaining patents, and foreign tax issues involving the six years of tax returns. P&G makes a variety of health, beauty, and pet care and other household products.

In one example, P&G says it donated the technology for an anti-periodontal disease rinse to Columbia University in 2004. It valued that donation at $19.5 million. The IRS allowed a deduction of only $4.9 million, the lawsuit states.

The IRS also sharply disagreed with the amounts of P&G deductions for providing chemical compounds for use in treating cancer and other diseases to the University of Arizona; fiber technologies for manufacturing paper products to North Carolina State University, and pest-control technology to the University of Florida, among other donations.

P&G valued artwork given to the Cincinnati Art Museum in 2003 at $8.5 million; the IRS allowed $6.4 million.

The company says in the lawsuit that it uses third-party appraisers to value its donations.

P&G says it paid federal income taxes of more than $6 billion over the six years that were audited.

The IRS has said about one out of six large corporations with assets of $10 million and higher, was audited in its 2007 budget year.

P&G spokeswoman Jennifer Chelune wouldn't comment Friday on the pending litigation, and the IRS didn't immediately respond to a request for comment. The lawsuit was filed earlier this month in U.S. district court in Cincinnati.