(Updates share move in paragraph 4, adds company's response in paragraph 5 and details from the release in paragraphs 8 and 10)

Feb 23 (Reuters) - Ratings agency S&P on Friday placed Paramount Global's credit rating on a negative watch, citing low operating cash flow generation at the media conglomerate due to the ongoing decline in cable television and competition in streaming.

S&P currently has a 'BBB+' - investment grade - rating on the firm, whose stock has lost about a fifth of its value this year in the face of weak revenue growth and a $15.63 billion debt load as of September that was more than its total assets.

"We believe FOCF (free operating cash flow) will be weaker than historical levels because the significant cash flows from the linear TV businesses will degrade rapidly as pay-TV subscribers continue to decline and advertisers migrate spending to streaming platforms," the ratings agency said.

Paramount's shares closed down 4.3% as rival Warner Bros Discovery reported a bigger-than-expected quarterly loss due to a weak advertising market and the impact of Hollywood strikes.

Paramount Global declined to comment on S&P's report.

The ratings agency said Paramount's cash flow declines have been more than its rivals due to "its smaller scale, less business diversification, and slower DTC (direct-to-consumer) ramp up."

The cash flow generated from DTC, or the streaming business, will be lower due to higher spending on content, investments in technology, and an increase in marketing and subscriber acquisition costs, S&P said.

The ratings agency said it plans to incorporate cash flow metrics more broadly for the media sector going forward.

After pouring millions of dollars into its fast-growing but unprofitable streaming unit Paramount Plus, the company said in November investments in the subsidiary had peaked a year ahead of the target.

S&P plans to resolve the negative watch on Paramount's credit rating after considering its fourth-quarter results, which the media company is expected to report on Feb. 28. (Reporting by Harshita Mary Varghese, Additional reporting by Jaspreet Singh in Bengaluru; Editing by Maju Samuel)