In a deal with 49 states aimed at thwarting sexual predators, MySpace said Monday it will tighten its security and privacy standards and step up enforcement of its age minimum of 14.

The deal, announced at a news conference in New York City, calls for MySpace to make profiles of teens aged 14-17 private by default and work to set up an e-mail registry that will let parents block their children from gaining access to MySpace or another social-networking site.

Jeremiah Owyang, an analyst at Forrester Research, said that the move by MySpace, with 110 million users, likely will force competitors to fall into line.

"You can expect others in that market ... to be likely to be very interested and adopt this same type of outreach," he said.

The voluntary agreement with MySpace, a unit of Rupert Murdoch's News Corp., is expected to heighten pressure on Facebook and other social-networking sites to adopt more stringent controls as well.

Hemanshu Nigam, chief security officer for MySpace, the No. 1 social networking site, and Fox Interactive Media, called on its competitors to sign on to the agreement.

"It's time to tell the industry: Step up," he said.

The agreement is the product of negotiations that extended for nearly two years, said Tom Corbett, attorney general of Pennsylvania, who noted that eight of the 27 people charged by the state's child predator unit in 2006 were MySpace users.

Though the attorneys general offered a carrot in praising the cooperation of MySpace, they added that a stick is available if need be.

If conditions call for "filing a lawsuit against MySpace … or others … we will do that," said Mark Dann, Ohio attorney general, who likened the Internet to the "wild west."

MySpace also agreed to:

--Review all images and videos uploaded to the site;

--Bolster its communication with consumers who report "inappropriate content or activity";

--Organize an industry task force to develop online safety tools, including identity authentication.

The attorneys general of all 50 states except Texas were party to the agreement.

In September, New York Attorney General Andrew Cuomo subpoenaed Facebook after undercover agents posing as underage users were solicited by adult sexual predators.

Mr. Cuomo's office said that Facebook also ignored complaints from investigators about inappropriate advances.

One month later, Facebook and Mr. Cuomo's office reached a settlement under which Facebook will more closely monitor complaints and allow a third-party Safety and Security Examiner report on its compliance for two years.

At the news conference, Connecticut Attorney General Richard Blumenthal said that parental involvement would supersede any technological safeguards.

"Ultimately, parents are our first and last line of defense," he said.