Sumner Redstone, who built a media empire that includes ViacomCBS with a string of high-profile takeovers, has died at the age of 97, his companies said Wednesday.

Statements from ViacomCBS and his National Amusements holding company announced that Redstone, who had been in declining health for several years, died late Tuesday.

Redstone built his company from a modest drive-in movie chain into a major cinema operator, maintaining leadership of the enterprise and prominence in the media industry well into his 80s.

In the 1980s, Redstone engineered a hostile takeover of Viacom, a spinoff of the CBS network that had become a major player in cable television and included the popular MTV music channel.

He later acquired Paramount Pictures, one of the major Hollywood studios, Blockbuster Entertainment and then led a merger with CBS.

In 2006, Viacom spun off CBS, separating the faster-growing cinema operations from the more sluggish broadcast assets, but Redstone remained in control of both through his holding company.

Sumner Redstone, the media mogul who led an empire that included ViacomCBS, is seen in 2007 -- he has died at the age of 97
Sumner Redstone, the media mogul who led an empire that included ViacomCBS, is seen in 2007 -- he has died at the age of 97 AFP / HECTOR MATA

The two firms reunited last year to become ViacomCBS.

In recent years, Redstone had been involved in litigation over his health and mental competency that seemed at times like a television soap opera.

His daughter Shari Redstone effectively controlled the empire with her father in reclusion, but other family members alleged he was manipulated by his daughter.

His granddaughter Keryn Redstone allied herself with the billionaire's ex-girlfriend Manuela Herzer, who had been waging a battle to have the ailing mogul declared incompetent.

At 92, Redstone stepped back from an operational role and became chairman emeritus at both CBS and Viacom amid a court battle over his mental fitness.