(Adds dropped word "on" in headline)
** Shares of Alumina Ltd AWC.AX fall as much as 4.5% to
A$1.375, their lowest since Nov 1
** The aluminium producer said output at its Portland
smelter in Victoria would be immediately reduced to about 75% of
its total capacity of 358,000 metric tonnes per year
** Morgan Stanley estimate the production cut to have $17
mln impact on AWC's 2023 net profit after tax
** MS keeps 'overweight' rating; A$1.75 PT
** Stock down 5.3% this year, as of last close
(Reporting by Poonam Behura and Rishav Chatterjee in Bengaluru)
((Poonam.Behura@thomsonreuters.com;))