In its announcement to the London Stock Exchange, the building society also announced the appointment of Robert Purdy as interim chief finance officer (CFO).
Stephen White, who has been acting as interim CEO, will leave the mutual to take up a new role with Santander.
Both appointments are subject to regulatory approval.
John Heaps, chairman of Yorkshire Building Society, said: “Alasdair Lenman has 23 years’ experience in finance and has worked in financial services for 15 years, most recently as our chief finance officer. He has played a leading role in the development of our existing strategy, which has yielded some of our strongest financial results in our history.”
Heaps added that the process to appoint the next permanent CEO was well advanced and would conclude as planned later this year.
Lenman added: “Yorkshire Building Society is enjoying its strongest trading performance in its over 150-year history. This is enabling us to reward our members with market leading savings rates and invest in the transformation of our business so we can deliver even further value to our customers. I look forward to supporting the society until the process for appointing a permanent chief executive officer concludes.”
