BP shares jumped nearly 7% Wednesday before paring the bulk of those gains after The Wall Street Journal reported that Shell is in early-stage discussions to acquire its British rival. If confirmed, the deal would represent one of the largest energy mergers in recent history and signal a dramatic consolidation of European oil and gas majors. Shell, in the meantime, denied that takeover talks are taking place. A Shell spokesperson told the FT that “This is further market speculation. No talks are taking place,”who added that the company…