** Shares of Australia's Calix CXL.AX jump 23.1% to A$0.64, hitting their highest since December 1
** Stock set for best day since mid November
** Environmental technology co executes a contract for the supply of magnesium hydroxide water treatment products to a new customer in the United States
** Deal is expected to generate up to A$10 million ($6.61 million) in additional annual product and services revenue
** YTD stock down 13.3%
($1 = 1.5126 Australian dollars)
(Reporting by Shruti Agarwal in Bengaluru)
((Shruti.Agarwal@thomsonreuters.com))