The new company will begin operating under the name Arcadium Lithium on January 4.Â
Arcadium will have a primary listing on the New York Stock Exchange, with CHESS depository interests (CDIs) traded on the ASX.
It will replace Allkem in the ASX200 on Friday, S&P Dow Jones Indices announced on Wednesday.
Allkem shareholders, who will own 56 per cent of Arcadium, cast 89.3 per cent of votes in favour of the all-scrip merger on Tuesday, with Livent shareholders giving their asset in the US overnight, Australia time.
"The strong support of Livent and Allkem shareholders for this transformational merger is a testament to the compelling value proposition of Arcadium Lithium," said Paul Graves, president and CEO of Livent and the future chief executive of Arcadium Lithium.
"We look forward to closing the merger and pursuing the opportunities to create greater long-term, sustainable value for all of our stakeholders."
Arcadium will be the world's third-largest producer of lithium, an essential component for electric vehicle batteries, behind US-based Albermarle and Chile's SQM.
Its global operations will include an open-pit mine at Mt Cattlin, WA, that produces the lithium ore known as spodumene concentrate for export to Asia.
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