Britain's largest bookmaker William Hill has appointed its operations director James Henderson as chief executive, turning to an insider to see the group through a challenging period for the industry.

Henderson, who has been with the group for 29 years, will replace retiring chief executive Ralph Topping on August 1.

Topping is stepping down after 44 years with the firm and six as CEO. 

The leadership change comes at a time when the gambling sector is facing huge financial pressure as the British government is tightening controls on betting shops and high-stakes gambling machines. 

William Hill has already announced the closure of 100 UK betting shops this year, blaming a tax increase on high-stakes gambling from 20% to 25%. 

"Whilst we face challenges as an industry, there are also plenty of opportunities to keep strengthening William Hill by further diversifying our revenues," Henderson said in a statement. 

Henderson, who joined the company 29 years ago as a trainee manager, will be paid a base salary of £550,000 a year and will be eligible for the firm's bonus plans. 

Topping was criticised by some shareholders last year for collecting a £1.2m retention bonus. 

He will remain an employee of William Hill, claiming a yearly salary of £650,000 and providing advice to the board whilst serving his one-year notice period that started on July 3, the company said. He will also be considered for a bonus.