General Motors will need to raise as much as $15bn in cash to shore up liquidity and bankruptcy is “not impossible” if the US auto market continues to slump, Merrill Lynch said, reports Reuters. Other analysts have suggested GM, whose shares fell to a new 54-year low on Wednesday, needs to raise funds to weather the downturn in the US auto market through 2009. But Merrill’s estimate of GM’s financing needs is the highest yet. It also carried the most stark warning of the bankruptcy risk for the largest US automaker. Merrill analyst John Murphy cut GM to “underperform” from “buy” and lowered his price target to $7 from $28. Shares fell as much as 11% to $10.50 in Wednesday’s trading as the cost to insure GM’s debt rose.