COPENHAGEN, Nov 23 (Reuters) - Danish grid operator Energinet signed deals on Tuesday with Belgium"s Elia (ELI.BR) and Germany"s 50Hertz that move Denmark closer to building two sea links connecting its offshore wind turbines to Germany and Belgium to boost the flow of green energy in the region. A massive expansion of offshore grid infrastructure is needed to meet the rising amount of renewable energy needed to enable European countries to slash dependency on fossil fuels while ensuring that volatile renewables become a more reliable source of energy. Energinet said a cooperation agreement signed with transmission system operator Elia edged them closer to a final investment decision on an interconnector between their two countries via a yet-to-be-built artificial island in the North Sea. With a relatively small coastline and limited access to offshore wind power in the Belgian part of the North Sea, Belgium needs to import green energy on a large scale. Energinet also inked a separate deal with German high-voltage grid firm 50Hertz, of which Elia owns 80%, on a power link to another planned hub which will be located on the Danish Baltic island of Bornholm. Denmark is planning to more than triple its offshore wind capacity by building two so-called energy islands - hubs for large volumes of power - linked to new wind farms in the Baltic and North seas to help meet ambitious climate change targets. With the new agreement, the three system operators will now be able to start feasibility studies and prepare business cases for the projects which would still require final investment decisions and national approvals to be realised. Reporting by Stine Jacobsen; editing by Emelia Sithole-Matarise