Niger Uranium Ltd's (URU.L) largest shareholder has called for an extraordinary general meeting to replace its chairman and expand the board after removing two current members, sending the uranium explorer's stock down 12 percent.

The investor, NWT Uranium Corp, has also sought shareholders to vote against a private placement proposed by the company, it said on Wednesday.

The proposed placement will result in a massive unnecessary and unfair dilution of existing shareholders, NWT said in a letter to Niger's board.

NWT, which directly owns 28.2 percent of Niger or 31.95 million shares, sought the re-constitution of the board by removing former CEO John Sanders and Non-Executive Director Wayne Beach, and adding four new directors, including Guy Elliot as executive chairman.

NWT wants the company's Non-Executive Chairman Ian Stalker, Finance Director Gordon Cassidy, and Non-Executive Director John Lynch, to be re-elected as board members, the letter said.

Niger Uranium said the board had resolved earlier this month to raise 2.5 million pounds by way of an equity placing with third party investors, to fund projects in Niger and the Henkries Project in Namibia.

Shares of Niger Uranium were down 1.5 pence at 11.5 pence at 1053 GMT. (Reporting by Balachander Surianarayanan in Bangalore; Editing by Gopakumar Warrier)

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