Macarthur Minerals (ASX:MIO) will voluntarily delist from the TSX-Venture Exchange and OTC Markets on May 16, citing low trading volumes and a mainly Australian investor base, according to a Wednesday filing with the Australian bourse.

The company will maintain its Australian Securities Exchange listing under the symbol "MIO" and said a single listing would reduce costs and improve investor access.

North American shareholders must transfer holdings to the Australian share register to continue trading, the filing added.

The Canadian register will remain open until July 11, after which remaining shares will be moved to an issuer-sponsored holding on the ASX, the company said.

Shares of the company fell 19% and earlier hit an all-time low.