NEW YORK - Software company Microsoft Corp. said on Tuesday it had filed 26 lawsuits that allege computer dealers sold illegal software.

The filings are part of the company's effort to crack down on intellectual property piracy.

The lawsuits, filed in Colorado, Georgia, Illinois, New Jersey, New York, Ohio and South Carolina, allege that the computer resellers pirated software or installed unlicensed software on computers they sold, Microsoft said.

"Our message should be made very clear by today's lawsuits," Mary Jo Schrade, senior attorney at Microsoft, said in a news release.

"We are committed to finding the unscrupulous dealers of pirated software and making piracy a business model that doesn't work."

Microsoft gathered evidence for these cases through the use of a program that is similar to a secret shopper concept. As part of its test purchase program, the company buys hardware and software from computer dealers across the country and then tests the software and software components to determine their authenticity, it said.

Shares of Microsoft ended up 19 cents or 0.85 percent at $22.48 on the Nasdaq on Monday.