A spokesman for the lender would not comment on whether there would be any high-profile departures but says this will be revealed over the next week.
The consultation will begin next week.
The lender previously made over 260 job cuts last October as a result of the worsening credit conditions. This latest move could see GMAC still left with around 400 employees.
GMAC says this move is in response to the adverse prevailing market conditions and the anticipated contraction of the mortgage market overall.
It insists it remains committed to the UK and providing mortgages to customers.
It says the move is part of its strategy to operate at a lower cost base in order to compete and to secure a strong position for the future.
Chief executive officer Simon Knight says: “Liquidity available for
mortgages has continued to diminish in the UK market into 2008. The reduction in our workforce is a direct response to current market conditions, and reflects our expectation that these conditions will prevail for some considerable time.
“In a much smaller market, with less liquidity generally, it is sadly necessary to take this step. We are committed to ensuring that affected employees are fully supported during this process.”
Knight adds: “GMAC-RFC has a long track record of success and we remain
confident in our long-term future. We are fully committed to the UK intermediary mortgage market but our short term strategy is to successfully negotiate the current adverse market conditions.”