Warren Buffett’s MidAmerican Energy on Monday funnelled $1bn in cash into Constellation Energy, its beleaguered takeover target, as EDF, Constellation’s French partner, considered whether to try to break up the deal with a higher bid.

Constellation, whose shares plummeted last week over concerns about liquidity within its commodities trading operation, reached a definitive agreement on Friday to be bought by MidAmerican, an energy company that is 88 per cent owned by Warren Buffett’s Berkshire Hathaway.