US activist fund Lone Star Value Investors has bought 5.3 per cent of Perth-based oil and gas junior Antares Energy and will force a vote to try to reform the board.

Lone Star said it wanted to add five “highly qualified independent directors" to the existing board, who would be able to turn around Antares’ performance. They had expertise in petroleum engineering, finance, capital markets and M&A, the Connecticut-based fund said.