Zimbabwe said on Thursday it had taken over majority shares from foreign mining firms which had not sold 51 percent of their equity to black Zimbabweans, without specifying which or how many firms were affected.

"All mining companies that have not complied, should note that 51 percent of their shareholding is now deemed to be owned by the state and any business transacted in respect of this 51 percent shall have been transacted on behalf of the government of Zimbabwe," indigenisation minister Saviour Kasukuwere said in a statement.

Zimbabwe passed new equity laws two years ago requiring foreign companies to cede 51 percent of their shares to "indigenous Zimbabweans".

The largest foreign miners in Zimbabwe have already reached deals with the government and should not be affected by the announcement.

Impala Platinum, Unki, owned by biggest producer of platinum in the world British-South African Anglo American, and Zimplats, the local unit of the world's second-biggest platinum miner South Africa, have offered to sell a part of their mines' shares to local communities and workers.

The announcement will be implemented retrospectively from September 25, 2011, when companies had to hand in plans on how they intend to sell their majority shares. Companies have to pay to the government its share in profits gained from that date.

"Any profits accruing to this 51 percent should be regarded as property of the state and any losses incurred will be charged against the company's assets, less the 51 percent indigenised portion, for any company that transacts without government involvement with effect from 25th September 2011."

"Companies are hereby advised that they are now dealing with assets of the state in respect of the 51 percent indigenised portion and any attempt to defraud the state will result in prosecution."