WASHINGTON—A technology executive pleaded guilty to federal wire-fraud charges on Tuesday, closing an obscure but potentially influential case that could shape future criminal prosecutions involving companies that provide bedrock internet services to customers.

Amir Golestan entered a plea on behalf of himself and his company, Micfo, at the end of the second day of a trial in federal court in Charleston, S.C., according to court records. He was accused of using fraudulent means to obtain thousands of internet protocol, or...

WASHINGTON—A technology executive pleaded guilty to federal wire-fraud charges on Tuesday, closing an obscure but potentially influential case that could shape future criminal prosecutions involving companies that provide bedrock internet services to customers.

Amir Golestan entered a plea on behalf of himself and his company, Micfo, at the end of the second day of a trial in federal court in Charleston, S.C., according to court records. He was accused of using fraudulent means to obtain thousands of internet protocol, or IP, addresses from the American Registry for Internet Numbers, a small Virginia-based nonprofit that allocates the addresses that computers use to communicate online.

The prosecution was the first federal case alleging fraud involving internet resources such as IP addresses. Legal and technical experts have said it could determine new boundaries for criminal behavior within the loosely regulated world of internet infrastructure.

The Wall Street Journal last year reported that the infrastructure hosted by Mr. Golestan’s company was used by criminals and hackers because it catered to virtual private network, or VPN, operators that allow users to hide their online activity. There is no evidence Mr. Golestan knew of the hacks, and hosting web infrastructure used by criminals isn’t in itself unlawful.

Micfo’s offices in Charleston, S.C., last year..

Photo: Byron Tau/The Wall Street Journal

Mr. Golestan, in an interview last year with the Journal, acknowledged creating 10 fictitious personas to pose as chief executives of 10 shell entities to obtain the IP addresses that he then used to build his business. Because the number of IP addresses is limited, they have value and can be bought and sold on the open market. Prosecutors allege Mr. Golestan created an elaborate web of fake companies and fictitious personas to acquire more IP addresses than he was entitled to from the internet registry.

Mr. Golestan told the Journal he broke no law and was engaged in the “victimless” use of pseudonyms to provide a service. The government alleged the IP addresses had a market value of about $14 million.

His attorneys didn’t respond to a request for comment concerning the guilty plea.

A wire-fraud charge carries a maximum sentence of 20 years in prison; however, in this case the actual sentence will likely be far lower for a first-time offender like Mr. Golestan and will be based on a variety of factors.

Micfo largely catered to other internet businesses that needed server space. Using the IP addresses Micfo was accused of obtaining illegitimately, Micfo’s customers sent a huge amount of untraceable internet traffic, some of it illicit or criminal, through the company’s servers, federal investigators said in subpoena documents reviewed by the Journal.

Federal investigators didn’t allege that Mr. Golestan and Micfo were part of or aware of illegal activity transmitted through the company’s servers. Rather, the Justice Department charged him and the company with defrauding the internet registry to obtain the IP addresses over a period of several years.

Mr. Golestan, who was born in Iran, started Micfo in 1999 in the bedroom of his childhood home in Dubai before emigrating to the U.S. Since the filing of charges against him in May 2019, most of Micfo’s employees have quit, and many of its longtime clients have left, the Journal previously reported.

Write to Dustin Volz at dustin.volz@wsj.com and Byron Tau at byron.tau@wsj.com