Architect HOK International has won a sought-after commission to design the £75m redevelopment of the Shell Centre on London’s South Bank.

The firm heard last week that it had seen off fellow American practices Gensler and Swanke Hayden Connell for the scheme, which aims to update Shell’s office space in the 26-storey tower, one of the most striking buildings in the Waterloo area.

A source close to the bidding process said HOK had been selected from a shortlist of seven firms. The work will involve revamping Shell’s office space at the same time as the firm seeks to reinvigorate its brand, which suffered last year after claims that it had overstated its oil and natural gas reserves.

The source said: “Shell wants to create offices that reflect its global aspirations for the company. There is no scheduled end date as yet.”

Despite the heavy investment in the Shell Centre, the Anglo-Dutch firm still has its headquarters in The Hague in Holland.

Other firms involved in the redevelopment include project manager Mace and M&E consultant Hurley Palmer Flatt.

Shell wants to create offices that reflect its global aspirations for the company

Source close to bidding process

HOK declined to comment on the appointment.

The refurbishment is separate from another scheme, Belvedere Court, which Shell is currently looking at with developer Lend Lease. The scheme, designed by consultant Arup, would involve building a new 10-storey structure next to the Shell Centre that would feature offices, retail and leisure.

Deputy prime minister John Prescott last year approved the scheme two years after Lambeth council had turned down the planning application because of the scheme's height and bulk, the fact that it overlooked the north block of County Hall, the impact that the retail space would have on existing businesses in the area and the loss of open public space.