This follows reports in the media that two US investment banks have made their biggest ever margin calls on the same mystery UK lender, while another has withdrawn its warehouse line to it entirely.
Reports suggest that the banks are believed to have funded at least £3bn in warehouse lines to the specialist lender.
But GMAC says it is not the specialist lender in question.
GMAC director of marketing Jeff Knight says: “When we saw the article in question, we too were scratching our heads as to who the lender in question could be. I can understand why the rumour mill points fingers at GMAC-RFC, because we are successful, high profile and front of mind.
“Unfortunately, there are far too many rumours flying around about GMAC RFC and other lenders that are damaging to our market. So here are some facts. GMAC-RFC has significant and sufficient levels of funding in place, not just for 2007 but for 2008 too. It also enjoys strong support from its parent GMAC ResCap.”
He adds: “Over the years, GMAC-RFC has built up a formidable reputation for trading assets and this remains to be the case too. The reality is that in today’s market, margin calls are a risk for every lender that funds through the wholesale market. Should it ever happen to GMAC-RFC, our strength and liquidity mean that we would be able to respond accordingly.”