** Shares of artificial intelligence startup CoreWeave CRWV.O rise 3.5% to $36.66 premarket

** Wall Street brokerages start coverage of the AI infrastructure provider on a broadly bullish note as IPO research quiet period ends

** J.P. Morgan starts with "overweight" rating and $43 PT

** Says CRWV enjoys backing of Nvidia NVDA.O, perhaps benefiting from premier status as a test bed for cutting-edge products

** Barclays starts with "buy" rating and a $48 PT

** Sees upside to CRWV's niche of selling the largest deployments to the most sophisticated customers and building infrastructure quicker than peers

** Goldman Sachs starts with Street-high PT of $54 and "neutral" rating

** "CoreWeave is a leading provider of AI compute at scale, sitting at the cusp of a massive paradigm shift"- Goldman Sachs

** The IPO was underwritten by a syndicate of 18 banks, led by Morgan Stanley, J.P.Morgan and Goldman Sachs

** Stock has fallen 11.4% since its Nasdaq debut last month

(Reporting by Padmanabhan Ananthan)

((Padmanabhan.Ananthan@thomsonreuters.com))