Copenhagen/Nuuk, Greenland  - Voters in Greenland, the world's largest island, are widely expected to approve a plan to gain more autonomy within Denmark in a referendum on Tuesday.

The Arctic island has had home-rule since 1979, and under the new terms Greenland aims to secure partial control over its natural resources and take greater charge of justice and legal affairs.

"We know Greenland has big resources," economics professor Christen Sorensen of the University of Southern Denmark and an expert on Greenland's economy said.

The resources include water power, minerals like zinc and diamonds and "there could be huge amounts of oil," Sorensen told Deutsche Presse-Agentur dpa by telephone from Nuuk, the capital of Greenland.

Sorensen, who has served as chairman of an economics advisory council for Greenland, said it would take time to explore the potential oil finds off Greenland.

Water power could provide cheap energy for aluminium smelters and Sorensen noted that US-based aluminium giant Alcoa was in talks with Greenland on production in Maniitsoq.

Shrimp and halibut fishing, currently the mainstay of the economy, are also to remain an important sector but needed to become more efficient, Sorensen said.

Greenland's workforce will also need better education and become more mobile.

The key aspect of the self-rule plan was that "Greenland has received the right to make their own decisions," Sorensen said.

Under the terms agreed between the parliaments of Denmark and Greenland, Danish subsidies known as the block grant, worth 3.2 billion kroner (542 million dollars), are to remain.

Potential oil revenues, if oil is found, were to be divided between Denmark and Greenland and deducted from the block grant.

Greenland could seek independence if the revenue is double the subsidy.

Several surveys suggest a comfortable lead for those in favour of enhancing Greenland's autonomy. About 85 per cent of the approximately 57,000 inhabitants are ethnic Greenlanders.

Main critics were the opposition Democrats, which draw support from Danish voters in Greenland and scored some 22 per cent in the November 2005 local legislative elections.

With a likely yes vote, the widened self-rule would be in place as of June 21, 2009, the 30-year anniversary of the current home rule bill.

Denmark would continue to manage foreign affairs and monetary policy even though Greenland has become more active in the Arctic region and maintains special ties with the European Union.

Sorensen said he expected Greenland to follow Denmark's lead even if Denmark were to introduce the euro. Such calls have been made in Copenhagen amid the current financial turmoil.

If the referendum passes, Greenlandic - an Inuit language - is set to become the official language.

Leading politicians from Greenland like Lars Emil Johansen of the ruling Social Democratic party Siumut welcomed this, as well as the fact that Greenlanders will be recognized as a people.

Johansen, a former head of Greenland's government, is also one of two legislators elected from Greenland in the Danish parliament.

At a recent briefing, Johansen said he hoped that Greenland would reach full independence in 2021 - the 300-year anniversary of the arrival of Danish-Norwegian missionary Hans Egede.

However, Johansen said he envisaged keeping ties with the Danish monarchy, similar to the British Commonwealth. (dpa)