March 20 (Reuters) - Chilean miner SQM and

state-run copper producer Codelco said on Wednesday that the

companies were extending the deadline to set terms on a

partnership by two months to the end of May.

In a separate statement, SQM said board member Xu Tieying

would step down on April 24. The announcements come on the eve

of an extraordinary shareholders meeting requested by China's

Tianqi Lithium Corp, a major shareholder in SQM.

Tianqi, which recommended Tieying for the board, did not

immediately respond to a request for comment.

The purpose of the meeting will be to hear about the status

of negotiations between SQM and Codelco, as well as "the detail

of the actions and contracts that are expected to be carried out

and executed."

Chile is the world's top copper producer and second-largest

lithium producer.