May 7 (Reuters) - Tesla supplier Piedmont

Lithium ( PLL ) has officially obtained a North Carolina state

mining permit after posting a $1 million reclamation bond to

develop an open-pit mine that would become one of the largest

U.S. sources of the key battery metal.

State officials formally awarded the 16-page permit to

Piedmont on Tuesday after a nearly three-year process, according

to regulatory filings. The permit was provisionally awarded last

month, pending the bond payment.