REYKJAVIK (AFP) - Icelandic singer Bjork and the chief of Canada's Magma Energy company are publicly feuding over Magma's planned purchase of an Icelandic geothermal power group.

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The artist, who was crowned Best Actress in Cannes in 2000, has led a public campaign against Magma gradually raising its stake Iceland's HS Orka, which produces energy from the island's geothermal power.

At a press conference on Monday, the 44-year-old singer called for a referendum on foreign ownership of energy resources and more transparency in talks around the deal, linking it to Iceland's banking collapse in late 2008.

Magma's chief executive Ross Beaty rebuffed the accusations and invited Bjork herself to buy shares in the company.

"I have a cheeky proposal to Bjork: if she is so worried about foreign investors buying HS Orka, why doesn't she, with all her millions, invest in buying some of HS Orka?," Beaty said, according to comments published on the website of the Reykjavik Grapevine, an English language magazine.

"I offer her a 25 percent stake at no profit to Magma -- she can buy the shares at exactly what it cost us... Let her put her money where her mouth is, as I am personally doing," he added.

On Tuesday, a statement from Bjork was posted on the Grapevine's website.

"Dear Ross. Noticed your message for me. You offering me shares in Orka shows that you totally miss my point," it read.

"I feel this company should not be privatised, it should be given back to the people," the singer said, reiterating she was not interested in shares.

Opponents of the takeover also charge Magma circumvented the law by establishing a Swedish sister company, as Icelandic regulations prevent firms from outside the European Economic Area to own an Icelandic power group.

Goethermal power is one of Iceland's most valuable natural resources.

According to the Financial Times, HS Orka is Iceland's largest privately owned energy producer, and produces nearly a tenth of Icelandic power.

Iceland's financial system nearly collapsed at the end of 2008 when its three major banks -- Kaupthing, Landsbanki and Glitnir -- went under.