Google, Yahoo! and Microsoft reached a $31.5 million agreement on Wednesday with the U.S. Attorney's office in St. Louis to settle allegations that they accepted ads from online gambling companies starting in 1997, reports MediaPost.

Although none of the companies admitted wrongdoing, Microsoft agreed to pay a $4.5 million fine, donate $7.5 million to the International Center for Missing and Exploited Children and provide $9 million for anti-gambling public service ads; Yahoo will also invest $4.5 million in public service ads and pay a $3 million fine, the same as Google.

All three companies said they stopped accepting online gambling ads as long ago as 1994.