NEW YORK — The Internet's key oversight agency relaxed rules Thursday to permit the introduction of hundreds, perhaps thousands, of new Internet domain names to join ".com," making the first sweeping changes in the network's 25-year-old address system.

The Internet Corporation for Assigned Names and Numbers unanimously approved the new guidelines as weeklong meetings in Paris concluded. ICANN also voted unanimously to open public comment on a separate proposal to permit addresses entirely in non-English languages for the first time.

New names won't start appearing until at least next year, and ICANN won't be deciding on specific ones quite yet. The organization still must work out many details, including fees for obtaining new names, expected to exceed $100,000 apiece to help ICANN cover up to $20 million in costs.

Domain names help computers find Web sites and route e-mail. Adding new suffixes can make it easier for Web sites to promote easy-to-remember names — given that many of the best ones have been claimed already under ".com."

New names could cover locations such as ".nyc" and ".berlin" or industries such as ".bank." The hefty application fees could curb a rush for individual vanity names, though larger companies might claim brands like ".disney."

The streamlined guidelines call for applicants to go through an initial review phase, during which anyone may raise an objection on such grounds as racism, trademark conflicts and similarity to an existing suffix. If no objection is raised, approval would come quickly.