By Sahil Patel

Walt Disney Co. has sold TrueX Inc., an advertising-technology company it absorbed as part of its $71.3 billion acquisition of 21st Century Fox assets in 2019, to Gimbal, a company that provides location-based technology and ad services.

Financial terms of the deal weren't announced. Gimbal, the customer-facing name of PaeDae Inc., paid less than $100 million for TrueX, according to a person familiar with the matter.

TrueX is best known for offering video-ad technology that asks users to interact with an ad before viewing content in exchange for fewer or no commercials. Some publishers use TrueX ad formats before TV shows or long-form videos on their sites and apps.

TrueX has pitched its approach as a way to improve both ad effectiveness and the experience for web users, among them, long-form digital video viewers accustomed to enduring multiple, often repetitive ad breaks.

Gimbal acquired TrueX to grab a bigger foothold in advanced TV advertising, said Rob Emrich, Gimbal's chief executive. That includes streaming TV as well as "addressable TV," a method that lets advertisers show different commercials to different households watching the same shows on more traditional platforms such as cable.

Addressable-TV ad spending in the U.S. will surpass $2 billion this year, and is expected to exceed $3.6 billion in 2022, according to research firm eMarketer.

"It's the fastest-growing part of our industry," Mr. Emrich said.

Gimbal wants to use TrueX's technology to, for instance, help marketers tell whether someone who browsed their products online is worth advertising to, and whether any such ad drove results, like a store visit.

TrueX's technology was attractive because of the firm's relationship with TV app owners, Mr. Emrich said, but also because its system solicits information on what viewers are interested in -- while also helping establish that they are real humans, not bots designed for ad fraud.

"Is this a real person because they are interacting with it?" Mr. Emrich said. "That's a huge problem in the industry."

21st Century Fox bought TrueX in 2014 for close to $200 million.

The Wall Street Journal reported in March that Disney was interested in selling TrueX, which it considered a noncore asset and operated as an independent subsidiary of Fox and Disney.

Mr. Emrich said Gimbal and TrueX combined are a profitable company, with revenue exceeding $100 million in 2019 and on a path to do the same this year. No layoffs are planned as a result of the transaction, he added.

Write to Sahil Patel at sahil.patel@wsj.com