Tanzania revoked a retention license for Barrick Gold Corp. and Glencore PLC's undeveloped Kabanga nickel joint venture in the country as part of a new mining regime, Reuters reported May 12.

A retention license is granted to holders of a prospecting license after they identify a mineral deposit of potential commercial significance but cannot be immediately developed due to certain constraints.

The Kabanga license, which was originally set to expire in May 2019, was one of the 11 canceled by the government under 2018 mining regulations. Retention licenses held by nickel, gold, silver, copper and rare earth exploration companies were also canceled.

In April, Tanzanian President John Magufuli appointed Idris Kikula as chairman for the country's new mining commission along with eight commissioners. This paved the way for tighter regulation of the sector.

The mining commission has been granted extensive powers to regulate and monitor the industry and operations in the country, under legislation passed in 2017.

"Consequent upon cancellation of retention license...rights over all areas which were subject of retention [licenses] are hereby and without further assurance reverted to the government", according to the new policy.

According to anonymous sources, Barrick and Glencore have been looking to sell their 50/50 Kabanga project since 2015 after a slump in nickel prices derailed the project.

Barrick's majority-owned Acacia Mining PLC is already in a prolonged tax dispute with Tanzania over mineral exports. Acacia owns the Bulyanhulu and Buzwagi gold mines in the country.