Madison Avenue isn’t sold on Elon Musk’s takeover of Twitter Inc.

Advertisers are concerned about the billionaire’s plans to soften content moderation and what they say are potential conflicts of interest in auto advertising, given that he is chief executive of Tesla Inc., say people familiar with the situation.

Some ad buyers said Twitter lags behind its competitors in providing so-called brand safety features. Joshua Lowcock, global chief media officer at UM Worldwide, an ad agency owned by Interpublic Group of Cos., called Twitter’s adjacency controls inadequate and “poorly thought through.”

Read more in the Wall Street Journal.