The field will reportedly be the source for the new Nord Stream continental pipeline.
In return, Gazprom will get a stake in E.ON's UK power stations, which include generators at Killingholme, Taylor's Lane, Cottam Development Centre, Enfield and Connah's Quay in Wales. It is thought that E.ON has so far offered Gazprom a share of its gas and power firms in Hungary - but the Russian giant wants more.
Gazprom has made little secret of its desire to break into the UK energy market and has consistently been linked with a takeover of Centrica, the owner of British Gas.
UK regulators would be put under pressure to block any deal that would allow Gazprom a share of the British market - in light of recent moves by Russian administrators, who forced Shell and BP to cede control of large-scale projects in Russia last year.
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