Tesco plc has announced that Dave Lewis will join the board of Tesco on 1 October 2014 as chief executive officer in succession to Philip Clarke. Clarke will continue as chief executive until that date when he will step down from the board but will continue to be available to support the transition until the end of January 2015.

“Current trading conditions are more challenging than we anticipated at the time of our first quarter interim management statement on 4 June,” said the retailer in a statement. “The overall market is weaker and, combined with the increasing investments we are making to improve the customer offer and to build long term loyalty, this means that sales and trading profit in the first half of the year are somewhat below expectations.

“The outlook for the full year will be influenced by the extent to which benefits from the investments we are making begin to be seen; by conditions in the overall market; and by any steps that may be taken during the remainder of the year to improve our customer offer further.”

Sir Richard Broadbent, chairman of Tesco, said: “Having guided Tesco through a substantial re-positioning in challenging markets, Philip Clarke agreed with the board that this is the appropriate moment to hand over to a new leader with fresh perspectives and a new profile. We are pleased to announce today the appointment of Dave Lewis, president, personal care at Unilever, as our chief executive from 1 October 2014. Philip Clarke will continue as chief executive until that date and will continue to provide support to Dave until January 2015. Philip will also remain chairman of our joint venture with CRE in China until that date.

“Dave Lewis brings a wealth of international consumer experience and expertise in change management, business strategy, brand management and customer development. He is already known to many people inside Tesco having worked with the business over many years in his roles at Unilever. The board believes that with Dave’s leadership Tesco will sustain and improve its leading position in the retail market.”

On appointment, Lewis will receive a basic salary of £1.25m and standard benefits commensurate with his position.