A study released by the Federal Trade Commission Thursday gives mixed reviews to the entertainment industry on the self-regulation of marketing violent content to children. The report is sure to reignite the years-old debate once more.

The findings show that the movie, music and video-game industries were generally complying with regulations. However, violent marketing directed at teen audiences remains substantially high.

Of the three, the video game industry has made the biggest steps to limit the sale of content to minors, whereas the movie and music industries lag behind by a significant margin.

"Self-regulation, long a critical underpinning of U.S. advertising, is weakened if industry markets products in ways inconsistent with their ratings and parental advisories," FTC Chairman Deborah Platt Majoras said, noting improvement but adding a lot of work still needs to be done.

Since 2000, the percentage of children able to purchase M-rated video games fell from 85 to 42 percent in 2006. However in the same period, the percentage of those able to purchase music content only fell from 85 to 76 percent.

The FTC also found that 39 percent of children could still purchase R-rated movie tickets, and 71 percent could buy unrated or R-rated films.

The success of the video game industry's effort to curb sales of 'M' rated games to minors could seriously damage the argument made by Democratic Senators Hillary Rodham Clinton and Joe Lieberman, who have both championed legislation to curb such sales.

On the subject of marketing, the FTC recommended that all three firms look over their marketing policies and ensure violent content isn't being pitched to children. It continues to also support self-regulation, taking First Amendment considerations into account.

Repeatedly, laws limiting the sale of violent video games have been struck down due to First Amendment concerns.

The Entertainment Software Association applauded Thursday's report. "We're pleased that the FTC has acknowledged what we in the industry have long-known: the best way to help parents are industry-led, self-regulatory efforts that can provide them information they need," senior vice president Carolyn Rauch said.