Tullow Oil said on Tuesday its Ghana unit filed for arbitration in London over two tax assessments the West Africa-focused oil producer received from local authorities.

The tax assessments Tullow disputes amount to $387 million relating to a period from 2010 to 2020, which the company says is in addition to taxes it has already paid to the Ghana government.

"Tullow believes that resolution through international arbitration will bring certainty, which is in the best interest of all stakeholders," the company said in a statement.

Tullow, which last month said the assessments are "without merit", said on Tuesday it is engaging with Ghana's government to resolve the dispute.

Separately, Tullow said the hearing for another request, for a separate international arbitration on a $320 million additional tax bill from Ghana, is scheduled in October.

(Reporting by Muhammed Husain in Bengaluru; Editing by Dhanya Ann Thoppil and Nivedita Bhattacharjee)