(Reuters) -Diageo said on Wednesday it has appointed Deirdre Mahlan as interim finance chief to succeed Nik Jhangiani who took over as interim CEO of the world's biggest spirits maker earlier this month.

Jhangiani was elevated to interim CEO after predecessor Debra Crew stepped down after just two years, during which shares in the maker of Johnnie Walker whisky and Don Julio tequila cratered.

Mahlan, a veteran in the spirits and beverage industry who previously served as the finance chief of Diageo for five years, will join as interim CFO from August 18, Diageo said.

Jhangiani said Mahlan brought extensive spirits experience as well as a deep knowledge of Diageo and its operations.

"I am delighted that she has agreed to return on an interim basis and I have full confidence that she will provide invaluable guidance to our teams," he said in a statement.

Until a permanent CEO and CFO are appointed, Mahlan will be responsible for taking over a plan set by Jhangiani to get the company's finances in order.

He has promised to cut costs and sell assets in a bid to reduce Diageo's debts, which had crept above the company's target range and concerned some investors, as well as to deliver higher free cash flows.

Overall, Mahlan spent 27 years at Diageo or its predecessor companies.

More recently, she was the CEO of U.S.-based luxury wine producer The Duckhorn Portfolio, ahead of its sale last year.

Diageo said in July that the search for a permanent CEO has already begun, with both internal and external candidates under consideration. It did not give a timeline.

Diageo reports full-year results on August 5. The company's shares were flat at 11:52 GMT.

(Reporting by Pushkala Aripaka and Yamini Kalia in Bengaluru and Emma Rumney in London; Editing by Sonia Cheema and Ros Russell)