The U.S. company that runs the internet's dot-com domain names has renewed its contract to do so for another six years, but won't be allowed to hike prices except under special circumstances.

That means the base cost of a wholesale ".com" web address will stay fixed at $7.85 US a year through 2019. Companies that resell the domains to consumers can charge more than that — or, if they're willing to incur a loss for promotional reasons, less.

There are about 100 million .com domains, a lucrative source of revenue for the Virginia company that runs them all. (iStock)

VeriSign Inc. runs the key directories that keep track of .com domain names under a contract with the Los Angeles-based Internet Corporation for Assigned Names and Numbers, a nonprofit organization that oversees internet address policies.

For every .com address on the internet, VeriSign collects $7.85, in exchange for ensuring the master directories of .com domains run smoothly amid increases in internet traffic and heightened security threats. The directories are used by millions of computers and mobile devices around the world to locate websites and send email to addresses ending in ".com."

The $7.85 fee translates to $785 million a year in revenue for the roughly 100 million existing .com names.

Had VeriSign been allowed to raise prices four times by seven per cent each, as called for in an earlier draft of its new contract, the company could have charged as much as $10.29 by the end of the six-year term. That would have meant an additional $244 million a year on those 100 million names.

The Internet Corporation for Assigned Names and Numbers tentatively approved that draft contract, but it needed the U.S. Commerce Department's approval. Commerce removed the price hikes and approved the modified contract Thursday.

VeriSign can still raise its fee for each .com domain registration over the next six years, but it will have to prove that cost increases justify a price hike.

Dot-com domain names typically sell for around $10 US per year, but some web-hosting companies will register a domain name for free for users who buy their other services.

VeriSign also operates the master directory of .net, .name, .cc and .tv domain names. With files from The Associated Press