Shares in Livent LTHM , the U.S.-based chemical manufacturer, gave up most of their gains to trade up just 1% in premarket action Wednesday, after it agreed to a $10.6 billion merger with Allkem AU:AKE , an Australian lithium miner. Allkem said an all-stock merger of equals would create a “leading global integrated lithium chemicals producer.” “Allkem and Livent, two global lithium chemicals companies, will combine their highly complementary range of assets, growth projects, and operating skills across extraction and processing under a vertically integrated business model with the scale and expertise to meet the rapidly…