Mr Last is currently head of strategic operations at Legal & General Savings Business.
Mr Davis' departure follows the acquisition of Cofunds by L&G in March. The group acquired 75 per cent share capital of Cofunds that it did not already own for £131m and hopes it will build on L&G's presence in the intermediary market.
Cofunds will remain a whole of market platform and a separate brand in the UK investment platform market.
Mr Davis has been chief executive since June 2011 when he joined Cofunds from Openwork.
{desktop}{/desktop}{mobile}{/mobile}
He said: "Cofunds has successfully transitioned to RDR and is in great shape to continue to service the needs of clients which makes now the optimum time to move on as it allows for a smooth transition ahead of the deal being completed.
"I leave the platform in the extremely capable hands of Chris Last, who'll be supported by a great team here which has the expertise and dedication to continue to evolve the proposition to meet the changing needs of clients now and in the future."
Mr Last said: "I am looking forward to working with the Cofunds team to build on the success they have already achieved. I believe we can help the platform move to its next stage of growth and development, while retaining its focus as a whole of market platform, serving both retail and institutional clients."

• Want to receive a free weekly summary of the best news stories from our website? Just go to home page and submit your name and email address. If you are already logged in you will need to log out to see the e-newsletter sign up. You can then log in again.