A private equity firm has agreed to pay roughly a half-billion dollars to buy Lytx Inc., a technology business that helps fleet owners monitor drivers and fleet activity.

San Diego-based Lytx was formerly called DriveCam, and its flagship product kept that name.

GTCR of Chicago agreed to buy privately held Lytx for more than $500 million in an all-cash transaction, Lytx announced on Feb. 18. The deal is expected to close before the end of the current quarter.

“Over this past year, video telematics pivoted from being a nice-to-have to a must-have among commercial and public sector fleets,” Lytx Chairman and CEO Brandon Nixon said in a prepared statement.

Nixon and executive management will stay, the company said.

“With an unrivaled set of solutions, services and blue chip clients, Lytx is already driving its strong vision of expanding the video telematics category,” said Phil Canfield, managing director of GTCR, in a prepared statement. Canfield said the company’s “clear market leadership is proof that the team can continue to record stellar results.”

Lytx has 66 percent of its market, according to the research firm Frost & Sullivan — roughly four times that of its nearest competitor at 14 percent.

Some 365 new companies adopted Lytx DriveCam programs during 2015, the company said. New clients include Swift Trucking, Martin Transportation Systems, HD Supply and the city of Atlanta. The company also said that nearly half its existing clients expanded the deployment of Lytx technology in their fleets.

Lytx said it had a record year in 2015, reporting 102,000 new subscriptions sold, bringing total subscriptions to more than 300,000.

The year saw Lytx book nearly $200 million worth of contracts.

DriveCam combines video capture of driving events, precise and personalized data-backed coaching for drivers, fleet tracking, fuel management and other services to help improve driver behaviors and reduce operational expenses. Lytx says its service protects and saves lives.

Nixon said the new funding provides opportunities.

“This new chapter will allow us to significantly expand the portfolio of services delivered to our growing installed base, and give us the room to deliver a broader variety of actionable data to help our clients solve tough business problems,” the CEO said.

A Lytx spokesman said the company’s plans include taking more office space in the building next door to its current building on Towne Center Drive.