Shell said “no talks are taking place” for a potential mega-merger with rival BP that would cost more than $80 billion and represent the biggest energy deal of the century. The denial comes on the heels of The Wall Street Journal reporting June 25 that Shell is in early talks to acquire BP in a much-rumored deal.

BP shares jumped as much as 10% after the Wall Street Journal reported that rival Shell is in early talks to acquire the British oil company. Shares of BP jumped $3.11, or 10%, to $32.94 in early afternoon trading. U.S.-listed shares of Shell, which is also U.K.-based, meanwhile, slid 3%.

U.S.-listed shares of BP climbed about 2% on Wednesday after The Wall Street Journal reported Shell was holding early-stage talks to acquire its oil rival.Citing people familiar with the matter, the outlet said BP was “considering the approach carefully” and talks were progressing slowly.