Duncombe will join the club from lender Abbey for Intermediaries, where he spent two years as head of sales.
Ben Thompson has been given an expanded role at the firm to develop opportunities across the its mortgage business while Stephen Smith becomes chairman of Legal & General Mortgage Club and will also oversee the group’s estate agency and survey businesses.
Duncan Crocker, managing director at Legal & General Network, said: “Jeremy has delivered very well wherever he has been and I know he will be a popular and successful appointment for us.
“He brings with him a wealth of experience in the financial services sector, with lenders and intermediaries and I am looking forward to working with him.
Last month, L&G said that it now accounted for a quarter of intermediated mortgages in the UK after strong growth in the past year.
“It is very important for us that we recognise the scale and standing of the Club as a strategic enabler,” Crocker added.
“We will continue to invest in providing the highest level of support for our members, to ensure we deliver the best service and propositions, as well as maximum all round value to all our trading partners, as well as for Legal & General.”