Poland and Norway have signed a major deal on natural gas deliveries including the construction of a 1,000km pipeline that will open up supply to the whole Baltic region.

The Polish Prime Minister, Jerzy Buzek, said the deal also had what he called "security aspects", becuase the country has been dependent on gas deliveries from Russia.

The agreement is worth $11.3bn (�7.8bn) and covers the delivery of more than 74 billion cubic metres of Norwegian gas to Poland.

A 1,000km gas pipeline will be built between the countries, which the two leaders said could be used for deliveries to other countries in the region.

The agreement still needs European Union clearance over competition concerns and sufficient gas orders in order to make the pipeline economically viable.

The left-leaning Democratic Left Alliance (SLD) opposition party in Poland has also rejected the deal ahead of elections later this month.

A consortium of gas companies on the Norwegian side - Statoil, Norsk Hydro, Shell, ExxonMobil and TotalFinaElf - will build the pipeline before the project comes on stream in 2008.