** Shares of Cokal CKA.AX soar much as 12.9% to A$0.079, set for their best day since late October - if current gains hold

** Iron and steel producer says it has signed a partnership agreement with commodities and investments house Cratus Group

** Says partnership to maximise the value of its Indonesian coal assets

** Says it will establish a 50-50 joint venture to increase capacity and efficiency of coal transport infrastructure; Cratus to inject $20 mln into JV

** Shares hit highest level since Nov 11

** Stock had fallen ~34.2% this year, as of 2333 GMT

(Reporting by Archishma Iyer)

((Archishma.Iyer@thomsonreuters.com;))