NEW YORK -Three years ago, the beginning of the end of the U.S. television business looked certain when one of the largest ad buying agencies vowed to move a big chunk of its purchases to YouTube from TV budgets.

The TV business did not die; far from it. Instead, data compiled by ad tracking firm MediaRadar at Reuters’ request shows some advertisers are spending more on television networks’ online properties and less on Alphabet Inc’s video service. The data may partially explain why Google’s parent had its slowest quarterly revenue growth in three years.

This week, the big U.S. TV networks plan to drive the knife further into digital rivals, repeating the phrase “brand safety” and exploiting YouTube’s struggle to curb unsuitable content, during the upfront ad sales period when TV networks preview the fall season for advertisers.

On stage and in private meetings, executives from Comcast Corp’s NBCUniversal, CBS Corp and Viacom Inc say they are pitching themselves as one-stop shops because they have viewers on TV, their own streaming services and YouTube.

“Across every screen, clients can rest easy knowing that their message is in a pristine, premium environment. And that’s something other platforms just can’t guarantee.”