Sweden-listed oil firm West Siberian Resources has signed a preliminary agreement to buy Alliance Oil in a stock deal valuing the Russian firm at about $1.5 billion. Gazprom is planning to boost energy cooperation with Iran, and an offer is to be made by the Russian company in mid-March. Gazprom’s plan to construct a 1,050-foot-tall skyscraper as its headquarters in St Petersburg has met opposition from 600 residents and activists. Russian electricity producer OGK-3, controlled by metals firm Norilsk Nickel, is considering “a range of acquisitions in the power sector,” including TGK-4.