Craiglist's adult services section is "the choice of traffickers" in sex with underage girls, an advertisement placed in a California newspaper said.

The San Francisco Chronicle reported on Thursday that the half-page ad, addressed to Craigslist founder Craig Newmark in Wednesday's San Francisco Chronicle, calls for Craigslist to discontinue its adult services section, which generated $36 million in revenues this year, and included the experiences of two teenage girls who said they were forced into prostitution via Craigslist.

His company is the only one that tries to curtail prostitution, using methods such as reviewing every ad, asking users to report suspicious activity and supporting law enforcement sweeps and stings, Craigslist Chief Executive Officer Jim Buckmaster said.

Buckmaster said, "We'd like to do even more, and my door remains open to experts from advocacy groups and law enforcement with ideas on how we can improve."

Malika Saar, the executive director of the Rebecca Project for Human Rights, the Washington organization that sponsored the ad said that visitors to the site's adult services section in California "will see what clearly children are up for sale."

The ad said, "Craigslist is the choice of traffickers because it's so well known and there are rarely consequences to using it for these illegal acts." (With inputs from Agencies)