Gazprom and Dutch Gasunie signed a letter of intent to explore the potential expansion of the Nord Stream pipeline to Britain.
It was one of several deals signed during President Vladimir Putin's visit to the Netherlands on Monday.
Gazprom chief Alexei Miller said the two companies discussed the possibility of increasing the Nord Stream pipeline with a line that will go to the United Kingdom. He said the capacity of the new pipeline would be about 27.5 bcm, the same as the capacity of each of the two existing pipelines.
"The key issue is to sign a long-term contract with our British partners to supply gas to the British market," Miller told reporters in Amsterdam.