By Eva Mathews and Tiyashi Datta

(Reuters) - Shares of ViacomCBS Inc, rebranded as Paramount Global, plunged 21% on Wednesday to their lowest in over a year, after the media company's earnings miss and its move to ramp up investments in streaming raised questions over its ability to stay profitable.

The company was a late entrant to the crowded video streaming industry, where Netflix and Disney+ have already carved out a big slice of the market by pouring billions of dollars into original content like "Money Heist" and blockbuster franchises like "Star Wars".

ViacomCBS said on Tuesday it would invest more than $6 billion by 2024 to create new content, $1 billion more than it had previously committed.

The steady stream of investments required to grow the business, including Paramount+, Showtime and BET+, will "limit margin expansion more than previously expected," Morningstar analyst Neil Macker wrote in a note.

Despite having a string of shows and films in the pipeline, including new installments of "The Quiet Place" and "Mission Impossible", the company's forecast to exceed $9 billion in revenue by 2024 in its direct-to-consumer (DTC) segment seems to have failed to impress.

MoffettNathanson analyst Robert Fishman said Paramount's losses will continue to mount, peaking at 2023 before improving as its content investment grows, while its traditional network TV business will come under pressure, limiting the company's ability to fully invest in streaming.

"Despite the big announcement of ViacomCBS changing its name to Paramount ... we are left with a similar question as we had last year: will the company be able to grow EBITA and FCF again to match prior levels?" Fishman said.

BofA analyst Jessica Reif Ehrlich, who downgraded the company's stock to "neutral", noted that her earlier "bullish thesis" was predicated on ViacomCBS being an attractive acquisition target amid a wave of media consolidation.

"It does not appear a potential sale is imminent, given the size of its investment in streaming," she said.

(Reporting by Eva Mathews and Tiyashi Datta in Bengaluru and Dawn Chmielewski; Editing by Anil D'Silva)