The survey, from a unit of Comcast called Strata, asked 83 advertising agencies which social platform their clients preferred for social media campaigns.
Sixty-three percent of advertisers said they were most likely to use photo-sharing app Instagram, compared with 56 percent who said they would use social network Twitter.
Facebook dominated, with 96 percent of advertisers saying they were likely to use it.
The survey comes hard on the heels of news that Snapchat is on track to overtake Twitter in active users in the United States.
Suffering stagnant user growth ad sales has been one of Twitter’s few bright spots.
It rejected the survey results pointing to another study in 2015 by Advertiser Perceptions that showed 37 percent of advertisers intended to buy ads on Twitter, compared with 28 percent on Instagram, which is owned by Facebook.
The same study showed that 46 percent were considering buying ads on Twitter compared with 41 percent on Instagram.
Twitter has 310 million users, Instagram has over 400 million.