MOSCOW (Reuters) - Trader Glencore has trimmed its ambitions to control Kazakh zinc producer Kazzinc, announcing a revised cash and shares agreement worth up to $1.4 billion, less than half the original deal, to raise its stake to just under 70 percent. The revised move - at a time when Glencore is in the final throes to take over miner Xstrata - values Kazzinc at a lower price and will involve less cash. That could reassure credit ratings agencies which had pointed to the purchase as one where the acquisitive trader, with a rating of two notches above junk, could cut back on cash strain. ...