March 3 (Reuters) - Shares of Marvell Technology Group Ltd fell on Wednesday as the designer of 5G networking chips predicted supplies could remain tight through its fiscal 2022. Marvell forecast revenue and adjusted profits for its current fiscal first quarter with midpoints of $800 million and 27 cents per share, respectively, in line with analyst expectations of $793.3 million and 27 cents per share, according to IBES data from Refinitiv. Marvell shares fell 3.4% to $43.90 in extended trading after closing down 4.7% earlier in the day. (Reporting by Stephen Nellis and Hyunjoo Jin in San Francisco; Editing by Leslie Adler)