Portugal ? For nearly seven years Stuart Lawley has tried to build a red-light district on the Internet, one that could help, at least nominally, keep pornographic Web sites away from curious underage eyes.

His efforts came to a halt for a third and possibly final time Friday when a key Internet oversight agency rejected his proposed “.xxx” address amid concerns the adult-entertainment industry that Lawley had courted was not unified in its support.

The Internet Corporation for Assigned Names and Numbers also feared that “.xxx” could force ICANN into a new, unwanted role as content regulator, even though the proposed domain name would be voluntary.

ICANN voted 9-5 to reject the application that Lawley and his company, ICM Registry LLC, had written and revised twice since 2000.

Lawley said a lawsuit against ICANN was likely.