The deal includes all broadcasts on ITV1 and its sister digital channel ITV2 from next month until the end of the year. It also includes one-off formats such as a Mother's Day special and a celebrity couples show.
Andy Robson, brand manager at Network Q, said: "Network Q is recognised as the leading used car programme in the UK and is delighted to be sponsoring 'Who Wants to Be a Millionaire?', the UK's highest-profile game show."
Network Q's sponsorship of the programme includes credits around the programme, involving a 15-second opening, six break bumpers, credits going in and out of each break and a 10-second closing sponsorship credit.
The deal was brokered by Peter Manten at Carlton Sponsorship and Andy Thornes at Initiative Media.
Previous sponsors of 'Millionaire' include Learn Direct and Alliance & Leicester.
Network Q is part of the General Motors-owned UK Vauxhall group, although it sells a complete range of second-hand cars in the UK and not just Vauxhalls.
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