MILAN (Reuters) - Swiss commodities trader Glencore confirmed on Monday the Italian tax authorities were reviewing some transactions between its plant in Portovesme and Glencore.

"All transactions were conducted in accordance with applicable Italian tax laws and on an arm's length basis between Portovesme and the Glencore Group," Glencore said in an emailed statement.

Italy's tax police said earlier on Monday they had uncovered tax evasion at a metals producer on the island of Sardinia to the tune of more than 120 million euros ($158.65 million).

A source told Reuters the company was owned by Glencore.

"Portovesme continues to engage with the tax authorities to ensure a swift conclusion to the review," Glencore said.

(Reporting by Stephen Jewkes, editing by Jennifer Clark)