Twitter's growth seen hinging on luring advertisers

(Reuters) - Twitter Inc's slowing revenue and user growth has raised further doubts about its ability to entice advertisers to spend more on its platform - at least in the near term.

Shares of the micro-blogging website operator, which warned on Tuesday that user growth was off to a slow start in April, fell 5.2 percent to $40.07 in early trading on Wednesday.

Twitter's market value fell by a fifth, or about $5 billion (3 billion pounds), on Tuesday after its disappointing first-quarter results were released in error an hour ahead of schedule.

At least 15 brokerages cut their price targets on the stock.

"...Simply put, advertisers aren't willing to bid up or spend as much with TWTR as expected," RBC analysts said in a research note, cutting their price target to $47 from $54.

Advertising has been seen as a growth driver for Twitter, but the RBC analysts said the company appears to have "hit an ROI (return on investment) wall with its advertisers."

Twitter's ad revenue per monthly average user has now decelerated for three consecutive quarters, and its outlook implied a further slowdown in the second quarter.

Analysts had expected the company's new advertising products, particularly its app install ads, to start driving growth in the latest quarter.

That didn't happen as much as expected.

Barclays Capital downgraded the stock to "equal weight" from "overweight" and Janney Capital to "neutral" from "buy."

Barclays cuts its price target to $44 from $60, while Janney cut to $44 from $53. Stifel cut its price target from $38 to $36, the lowest among brokerages that cut their price targets.

Twitter has been making big product changes to boost user growth, but user numbers grew by just 18 percent from a year earlier in the quarter - the slowest growth in five quarters.

"We have been optimistic, longer-term, on Twitter’s ability to monetize their logged-out user base and we continue to see that as an opportunity," Barclays analyst Paul Vogel wrote.

"All of these things, unfortunately, look like they may take some time."

So far, Twitter's efforts to capture more revenue per user pale when compared with social media rival Facebook Inc.

Facebook reported last week that it had 1.44 billion monthly active users, generating revenue of $3.54 billion - about $2.46 per user. Twitter's 302 million users generated $436 million in revenue - or about $1.44 each.

"TWTR is several years behind FB in its monetization story ..." MKM Partners analyst Rob Sanderson wrote in a note.

(This story corrects the share movement and price in the second paragraph)

(Reporting by Tenzin Pema and Supantha Mukherjee in Bengaluru; Editing by Ted Kerr)