April 23 (Reuters) - TransAlta Corp TA.TO :
* MANGROVE PARTNERS COMMENCED AN ACTION IN ONTARIO SUPERIOR COURT OF JUSTICE AGAINST TRANSALTA CORP, ITS DIRECTORS, BROOKFIELD BRP HOLDINGS
* MANGROVE PARTNERS - SEEKS RELIEF UNDER OPPRESSION REMEDY PROVISIONS, ASKING COURT TO SET ASIDE BROOKFIELD DEAL WITH TRANSALTA