** Shares of Ambuja Cements ABUJ.NS climb 1.9% to 484 rupees, while Orient Cement ORCE.NS rises 2.3% to 334.95 rupees
** India's antitrust watchdog on Tuesday approved Ambuja's acquisition of Orient, months after the Adani Group company first announced the deal
** ORCE set for busiest trading session in over four months, with volumes at 6.8x the 30-day avg; ABUJ's vols relatively muted at about 0.3x its 30-day avg
** ABUJ on track to for biggest one-day gain in a month, ORCE for best day in more than 3 months
** ABUJ stock rated "buy' on avg, ORCE rated "sell" - data compiled by LSEG
** Ambuja and Orient are down about 11% and 4.5% YTD, respectively
(Reporting by Manvi Pant in Bengaluru)
((Manvi.Pant@thomsonreuters.com; +918447554364;))