Hundreds more workers face redundancy because another part of MG Rover company has gone into administration.
Phoenix Venture Motors (PVM), which lost £2.5 million last year, has 472 workers based in the Midlands, North-west and South of England, at dealerships selling new and used cars as well as offering spares and servicing.
PricewaterhouseCoopers, administrators to MG Rover, were appointed yesterday by PVM, which was owed a " substantial" sum of money by MG Rover.
Joint administrator Rob Hunt said the directors of PVM were left with little option, but to seek an administration order.
"We will be working with management to quickly establish which of the sites can remain open and continue to trade so as to preserve parts of the distribution channel for MG Rover cars."
PVM has dealerships in Preston, Chorley, Coventry, Northampton, Rednal, Bromsgrove, Kidderminster, Hatfield, Romford, Oxford and Muswell Hill, London.
Three of the PVM dealerships have already closed, with the loss of 86 jobs, the administrators announced. The dealerships are in Northampton (18 redundancies), Oxford (25) and north London's Muswell Hill (43).
Details of the latest job losses came as it emerged that a telephone helpline set up by the MG Rover Task Force to give advice to Longbridge workers and their families has taken more than 4,000 calls in a little more than a week.
Advisers gave information about benefits, tax, pensions and new jobs to 1,200 callers over the weekend alone, after the car firm's final collapse was announced.
Regional development agency, Advantage West Midlands, which is co-ordinating the task force on behalf of the Government, has also established an employer job match helpline to put firms wishing to take on new staff in touch with sacked Longbridge workers.
JobCentre Plus offices in Northfield and across the city have pledged to interview up to 1,000 former MG Rover employees a day.
It is hoped that all of those made redundant will have been seen by JobCentre Plus by this Friday.
The second meeting of the task force yesterday agreed to extend the Government's compensation package to hundreds of sacked workers at the Peugeot car plant in Coventry who were made redundant earlier in the year.
Details of a £50 million skills and training package for former Peugeot workers will be announced shortly.
It was also decided to earmark £24 million to help viable components companies cope with the demise of MG Rover.
Twenty-four companies have been assisted so far with grants totalling £300,000. More than 700 jobs have been safeguarded.
The Engineering Employers' Federation has agreed to provide a brokerage service to ensure that apprentices at MG Rover continue to receive training.
A network of Further Education Colleges across the West Midlands has been established to co-ordinate an offer for retraining opportunities
Nick Paul, chairman of Advantage West Midlands and the MG Rover Task Force, said: "Yesterday's meeting was the first since the announcement of large-scale redundancies at MG Rover on Friday.
"Putting in place support for 5,000 workers affected was therefore our priority.
"I am pleased to announce that every worker will be seen this week to make their benefit claim.
"Also, the job match hotline can start matching former MG Rover employees to prospective new employers.
"The hotline number was established in response to the many calls we received from businesses last week.
"Just as importantly is the skills and retraining help for workers, more details of which will be announced in the next few days.
"Jobcentre Plus offices across the region are on stand by, supplemented by skills advisers to help workers find new jobs."