The US Treasury today unveiled the scale of its latest Detroit rescue package, agreeing to pump $6 billion (£4.1 billion) into General Motors' finance company GMAC.

The government hopes the measure will restart lending to car buyers and help raise revenue at the ailing giant GM, whose Vauxhall factories in the UK employ 5500 staff in Ellesmere Port and Luton.

GM Europe is still seeking separate assistance from the UK Treasury.

The move by Washington, the latest in the White House bid to stave off bankruptcy at GM - led by Rick Wagoner - and Chrysler, consists of a $5 billion government stake in GMAC and a $1 billion loan to GM to participate in a rights offering at GMAC as part of its reorganisation as a bank.

"This is part of our strategy to position GMAC for long-term stability," said Toni Simonetti for GMAC.

"The reason we're doing this is so we can provide credit to consumers. We'll put these funds to use right away."

The latest rescue comes as billionaire investor Kirk Kerkorian gives up on Detroit, having sold his Ford stake at a big loss. He spent about $1 billion acquiring a 6.5% stake in Ford. Ford was trading at about $7.75 a share when he began acquiring his stake while the average price since he began selling in late October has been $2.33 a share.

The federal loan to GMAC is in addition to $17.4 billion the Treasury agreed to lend to GM and Chrysler earlier this month. The fresh capital comes from the Treasury's $700 billion Troubled Asset Relief Programme (Tarp) originally intended to help banks.

GM's US sales plunged by more than 22% this year after GMAC - which financed about 35% of its retail customers last year - ran short of cash and began to limit loans.

The Treasury stepped in after Congress failed to pass an auto industry bailout earlier this month. GMAC has been racing to rebuild itself as a bank in order to qualify for access to the Tarp funds. It finally won Federal Reserve approval last week after raising additional capital.

The company, co-owned by GM and private-equity firm Cerberus, has lost $7.9 billion over the past five quarters as the credit crunch lifted its borrowing costs sharply and the value of many of its assets plunged.