GMAC UK has teamed up with SsangYong UK following the start of a similar arrangement with MG Motor.
Both are described as “multi-year” agreements – the terms of the contracts remain confidential.
Originally part of General Motors, GMAC is now a division of Detroit-based Ally Financial Inc.
India’s Mahindra & Mahindra engineering group has a 70% stake in Korean carmaker SsangYong.
The 54 SsangYong UK dealers can arrange wholesale financing through GMAC, which also provides retail loans for their customers.
GMAC is the “preferred” supplier, so SsangYong dealers are free to sell other firms’ financial products.
Paul Williams, SsangYong Motor UK chief executive, said GMAC was appointed after a rigorous selection process.