From Kevin Melrose:

At the risk of appearing pedantic, Warner Bros. didn’t buy DC. Kinney
National Company, which began as a parking-lot company, went on a buying
spree in 1967, purchasing National Periodical Publications, the talent
agency Ashley-Famous and the movie camera/equipment company Panavision.
Two years later Kinney purchased Warner Bros.-Seven Arts, which was
hurting for cash.