ViacomCBS renames itself as it plays catch-up with Paramount+, its streaming service.

On Tuesday, Shari Redstone staged her second hourslong investor presentation in two years. Both events were designed for the same purpose — to reposition her old-line media company, ViacomCBS, as a streaming giant in the making, one capable of competing head-on with Netflix, HBO Max, Disney+ and Amazon Prime Video, despite a late start.

This time, there was less snickering.

“Some of you thought we were on an impossible mission,” Robert M. Bakish, the chief executive of ViacomCBS, said during the presentation on Tuesday. “It’s not only possible. It’s happening.”

To highlight the importance of its fast-growing Paramount+ streaming service, Ms. Redstone, the company’s chair, announced that ViacomCBS would rename itself Paramount Global.

Paramount+ had 32.8 million subscribers worldwide at the end of its most recent quarter, up from fewer than 19 million a year earlier. In the three months that ended on Dec. 31, Paramount+ added 7.3 million customers, the result of offerings like “1883,” the prequel to “Yellowstone”; “Clifford the Big Red Dog”; and National Football League games. (A year earlier, ViacomCBS was adding about a million streaming subscribers a quarter.)

The company’s streaming portfolio (Paramount+ and niche services from Showtime, BET and Nickelodeon) now has about 56 million subscribers. Mr. Bakish said that number would grow to 100 million by 2024, more than the roughly 70 million the company had previously forecast. The company also raised its 2024 streaming revenue goal to $9 billion, from $6 billion.

Streaming brought in about $4.2 billion last year, including advertising sales from the free Pluto TV service.

Paramount+ unveiled a barrage of additional programming to fuel continued growth. The expanded lineup will include fresh content from franchises including “Yellowstone,” “Beavis and Butt-Head,” “Teenage Mutant Ninja Turtles,” “Real World,” “Dora the Explorer,” “NCIS,” “SpongeBob SquarePants,” “Transformers” and “South Park.” Paramount+ will be the exclusive first stop after theatrical distribution for all Paramount Pictures movies beginning in 2024. (Many previously went to Epix, a premium cable channel.)

Starting this summer in the United States, Paramount+ subscribers will be able to upgrade to receive Showtime content, including the new hit drama “Yellowjackets” and older series like “Billions.”

ViacomCBS shares declined about 6 percent in after-hours trading. Richard Greenfield, a founder of the research firm LightShed Partners, cited investor concern about Mr. Bakish’s “meaningfully stepping up spending” on content.

It may be growing quickly, but Paramount+ continues to lag behind competitors like Disney+, which added 11.8 million subscribers worldwide in its most recent quarter to reach 129.8 million. Netflix has about 222 million.