Advertising-technology company Videology has filed for chapter 11 bankruptcy protection, with a deal to sell its assets to Amobee, the ad-tech division of Singapore-based telecommunications company Singtel.

Amobee will be the “stalking horse,” or lead bidder, which is designed to set a floor price to encourage other potential bidders to submit higher offers, Videology said in a statement Thursday, confirming an earlier report in The Wall Street Journal. Amobee has agreed to pay for about $45 million for Videology’s assets, according to people familiar with the matter.

Videology filed for chapter 11 in the U.S. Bankruptcy Court for the District of Delaware on Thursday. The filing states Videology has estimated liabilities of more than $100 million. The filing lists the company’s assets at $86.5 million.

GroupM, the media-buying arm of WPP PLC, was listed as the creditor with the largest unsecured claim against Videology. Across various divisions, GroupM is owed more than $35 million by Videology, according to the filing. GroupM also holds approximately 3% of Videology’s shares.

In a statement, Videology’s founder and chief executive, Scott Ferber, said the transaction “represents the best path forward for Videology and is in the best interests of all our stakeholders.”

Singtel and Amobee declined to comment.

Videology secured significant funding several years ago thanks to its narrow focus on video advertising and its early bet that TV advertising would become more digital and data-driven. But since then, the company has struggled to maintain revenue growth.

Ad-tech companies, once a hot attraction for investors, have been beset with increasing turbulence in recent years in a digital advertising market dominated by Google and Facebook. Some of the recent deals in the industry reflect those changing fortunes. Notably, Rocket Fuel, a public ad-tech company once valued at $2 billion, sold last year to rival Sizmek for $125.5 million.

Videology last raised equity in 2013, funding that valued the closely held company at $300 million, according to a person familiar with the matter. The company raised total venture funding of more than $130 million and took out an $80 million credit facility with FastPay and Tennenbaum Capital last year. The company’s investors include Comcast Corp. and venture capital firms New Enterprise Associates and Valhalla Partners, according to the bankruptcy filing.

Videology was founded in 2007 by Mr. Ferber, an ad-tech veteran who co-founded and sold an early online ad company, Advertising.com, to AOL for $435 million in 2004.

Videology creates software that enables advertisers and publishers to use data to place and measure their video ads on digital platforms and television. The company originally ran an ad network model, facilitating advertisers wanting to buy video ads across a range of websites and taking a percentage of their media spend. But that model has fallen out of favor with many large ad-buyers and publishers in recent years.

In 2015, Videology shifted to focus more on what it calls the “advanced television” space, charging a recurring fixed fee to help media companies sell TV and premium online video ads using granular data targeting.

But growth in its advanced TV business hasn’t made up for declines in Videology’s legacy, digital-only business. A person familiar with the matter said Videology’s 2017 revenue was slightly lower than the 2013 level.

“The industry is only in the early-stages of the TV and video transformation that we were built to power, and it will take resources, capital and time to help transform a market as large as TV,” Mr. Ferber said in the statement.

Amobee was acquired by Singtel in 2012 and became the telecommunications company’s digital advertising division. It has been steadily amassing a stack of ad-tech companies as it looks to bolster its offering to advertisers. Last year, it acquired Turn, a U.S.-based firm specializing in ad-buying and analytics software, in a deal valued at $310 million.

Videology would help Amobee expand its client and technology footprint. An acquisition would be subject to court approval.

Write to Lara O’Reilly at lara.o'reilly@wsj.com