** Amsterdam-based AI infrastructure firm Nebius Group's NBIS.O shares fall 3% to $126.01 premarket

** NBIS unveils planned offering of $3.75 billion worth of convertible bonds in two series

** Proceeds will be used to fund construction and build-out of its data centers, among other purposes

** Stock closed up 15% on Monday after NBIS unveiled mega AI capacity deal with Meta META.O worth up to $27 billion over five years

** Last week, AI behemoth Nvidia NVDA.O said it will invest $2 billion in NBIS to buy an 8.3% stake

** NBIS has 253 million outstanding shares, per LSEG data

** 10 of 12 brokerages rate the stock "buy" or higher and 2 "hold"; median PT $150 - data compiled by LSEG

** As of last close, NBIS stock up 55% YTD

(Reporting by Arasu Kannagi Basil in Bengaluru)

((ArasuKannagi.Basil@thomsonreuters.com;))