Global travel agency Thomas Cook Group PLC (LON:TCG) said Wednesday it will slash its British and Irish workforce by 2,500 as it struggles to adapt to competition from internet travel sites by cutting costs.

The 171-year-old London-based company said it will cut by 16 percent its payroll in U.K. and Ireland, adding that it will close 195 of its 1,069 offices in Britain and Ireland, where it employs 15,500 people. About 900 of the 2,500 positions being eliminated are administrative or managerial.

The staff reductions are part of the company's three-year restructuring plan to adapt to a market increasingly dominated by internet-only services that let tourists book their own vacation travel and related activities. The turnaround plan aims to reduce costs in the U.K. business by £140 million ($211 million).

Shares have jumped 80 percent this year after tripling in value last year, Bloomberg said. That's a contrast to 2011 when shares plunged 92 percent.

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