(Sharecast News) - Thomas Cook on Friday announced plans to close 21 stores and make 320 retail staff redundant as it refocuses on its online presence.Following a review of its retail workforce the travel agent said it would reduce its chain of shops to 566 in order to streamline its UK network as part of a wider efficiency programme.A consultation process with the affected staff and their union representatives has begun.Chief of Tour Operating, Will Waggott, said: "Today's announcement reflects the wider challenges seen on the high street, with more and more customers choosing to book online. These measures will help us to drive greater efficiencies across Thomas Cook so that we relentlessly focus our resources in those areas that give us the greatest opportunity to make a difference to customers in our core holiday offering."Almost two thirds of all Thomas Cook bookings in the UK last year were made online and growth in online has been the fastest in all sales channels, rising by 30% through 2018 according to the London-listed company.Furthermore 40% of Thomas Cook holidaymakers departing from the UK now use the company's app to help manage their holiday."Looking ahead, we will be working to ensure that Thomas Cook is fit for the future, putting a rigorous focus on costs in a competitive environment while giving customers more reasons to holiday with the strongest brand in travel," said Waggott.Thomas Cook's shares were down 4.05% at 27.46p at 1116 GMT.