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By Simon Zekaria

LONDON--Whitbread PLC (WTB.LN) Friday said Alison Brittain will become the chief executive of the coffee retail chain, hotel and restaurant group next year, replacing Andy Harrison.

Whitbread--which owns the Costa Coffee chain of stores and Premier Inn budget hotels, as well as restaurant brands, Beefeater, Brewers Fayre, Table Table and Taybarns--said Ms. Brittain, 50, will join the company on Jan. 4.

She is currently group director of the retail division at Lloyds Banking Group PLC (LLOY.LN)and a non-executive director of retailer Marks and Spencer Group PLC (MKS.LN). She has held senior banking roles at the U.K. business of Banco Santander S.A. (SAN.MC) and Barclays PLC (BARC.LN), Whitbread said in a statement. Ms. Brittain will become the sixth woman in charge of a FTSE 100 company.

Mr. Harrison, who announced his departure last month, will retire from all executive roles at the end of February 2016, after leading the company for five years. Under his tenure, Whitbread's stock market valuation has soared as the group profited from a boom in demand for coffee shops and budget accommodation, including from business travel. The group also expanded abroad by taking both Costa Coffee and Premier Inn to destinations globally, from Europe to China.

"Alison has vast experience in successfully managing multi-site operations with leading brands," said Whitbread Chairman Richard Baker.

Ms. Brittain said: "Whitbread has a clear strategy and I am looking forward to leading the company as it grows and delivers for its customers, its people and its shareholders."

By 2020, Whitbread said it aims to have 85,000 Premier Inn U.K. rooms from around 60,000 and Costa Coffee sales of around 2.50 billion pounds ($3.92 billion) from GBP1.4 billion.

Ms. Brittain will have a basic annual salary of GBP775,000 and is buying around GBP500,000 worth of shares in Whitbread, the company said.

At 0935 GMT, shares fell 1.1% to 5,205 pence.

Write to Simon Zekaria at simon.zekaria@wsj.com

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