Toronto-headquartered Barrick Gold has presented a proposal to its London-listed subsidiary Acacia Mining to buy the rest of the shares in the miner that it does not already own for $285-million.

The share-for-share exchange of 0.153 Barrick shares for each ordinary share of Acacia implies a value of $787-million for the Tanzania-focused miner.

In a statement late on Tuesday, Barrick explained that the government of Tanzania, with which it had been negotiating for two years to seek a basis for a settlement of Acacia’s disputes, had refused to enter into an agreement directly with Acacia.    

The mining company is embroiled in a long-running tax dispute with the country. The miner was also forced to cut output by a third after the government banned the export of mineral concentrates from the Bulyanhulu and Buzwagi mines, in 2017. On Monday, the government fined Acacia $2.4-million for alleged pollution at its North Mara mine.

Barrick CEO Mark Bristow recently said that Acacia was not cooperating in solving the disputes in Tanzania, a notion that Acacia interim CEO Peter Geleta rejected.

Acacia said on Wednesday morning that it continued to be excluded from discussions between Barrick and the Tanzania government.

It stated that Barrick had provided it with a letter from the government negotiating team, which stated that it would not execute final agreements for the resolution of the disputes if the company was one of the counterparties to the agreements, and that it would only sign such agreements "if satisfied that substantial changes have been made to the management style of the operating companies and of their shareholders".

Acacia closed 5.60% up on the London exchange on Tuesday at 159.50p a share, giving it a market capitalisation of £654.09-million, or about $830-million. The company listed on the main market of London in 2010, at the time still known as African Barrick Gold.

Barrick closed relatively unchanged at $12.12 a share on the NYSE and down 1.22% at C$16.25 a share on the TSX.