Diageo is looking to recruit a new chairman as its existing one Franz Humer is stepping down, fuelling rumours of a shake-up in its board.

The Swiss-Austrian businessman took charge as chairman of the £48bn company in 2008, reported The Spirits Business.

Rumours regarding Humer’s exit began last December when media reports indicated that the maker Johnnie Walker had appointed JCA Group to scout for a non-executive director with requisite skills to replace its existing chairman.

"The board has clearly started to think about succession and a process is underway."

Humer was non-executive director in Diageo in 2005.

He will be 70 on 1 July and is expected to announce his retirement at the end of July, when Diageo will reveal its 2015-16 full-year results.

He is expected to officially exit at the annual meeting in the autumn.

When Humer was appointed as non-executive director of Diageo in 2005, the firm was witnessing rapid expansion under its former CEO Paul Walsh, who stepped down in 2013.

A spokesperson for the firm was quoted by The Spirits Business as saying: "Dr Humer has been our esteemed chairman for eight years guiding the company to the leadership position we have today."

The company also told The Sunday Times: "As a matter of good governance process, the board has clearly started to think about succession and a process is underway. At the appropriate time we will announce our plans for succession."