** Shares of Cokal CKA.AX rise as much as 15.3% to
A$0.098, their biggest intraday percentage gain since April 10
** Stock hits its highest level since June 21
** The coal miner signs a deal with Indonesia's Petrosea
PTRO.JK to ramp up production at co's Bumi Barito Mineral
metallurgical coal mine
** Sees lower production costs per ton at the mine from deal
** Avout 925,000 shares change hands, compared with the
30-day average volume of around 535,000
** Stock trims YTD losses to 20%, including session's moves
(Reporting by Aaditya Govind Rao in Bengaluru)
((Aaditya.govindrao@thomsonreuters.com;))