German energy company BASF said it was exiting the gas trading and storage business after swapping assets with Russian natural gas company Gazprom.

BASF, its subsidiary Wintershall, and Gazprom completed swaps of assets of equivalent value, giving the German company a stronger production portfolio.

"With the swap, BASF is further expanding its production of oil and gas and has exited the gas trading and storage business," the company said in a statement.

Wintershall gets a quarter of Gazprom's holdings in Western Siberia, which the German energy company said could produce at least 280 billion cubic feet of natural gas once operations start in 2018.

In exchange, the Russian company acquires gas storage facilities in Germany and Austria, as well as a stake in Wintershall oil and gas operations in the southern waters of the North Sea.

Gazprom in early September signed a shareholder agreement on the development of the second phase of the twin Nord Stream pipeline system in the Baltic Sea with German energy companies BASF and E.ON, French company ENGIE, Austria's OMV and Royal Dutch Shell.

Under the proposed expansion, two more lines would be added to the existing network running to the German coast, bringing the net aggregate annual capacity to 1.9 trillion cubic feet of natural gas.

The project will be developed by a company named New European Pipeline, where Gazprom would hold a 51 percent share, E.ON, Shell, OMV and BASF would each get a 10 percent stake and ENGIE left with the remaining 9 percent.