Macarthur Minerals (ASX:MIO) said it will raise AU$250,000 through the issue of unsecured convertible notes to a sophisticated investor, according to a Tuesday filing with the Australian bourse.

The notes, which carry a 10% annual interest, mature in 12 months and are convertible at AU$0.015 per share at the investor's election.

Shares of the company fell 5% at market close.