William Hill has said that its chief executive is stepping down with immediate effect after less than two years as CEO of the bookmaker. James Henderson, who took charge at the UK's biggest betting firm in August 2014, will be replaced by chief financial officer Philip Bowcock until a permanent successor is found. Henderson had spent more than 30 years at the firm.

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In a surprise announcement, chairman Gareth Davis said of his departing chief "we would like to thank him for his significant contribution and we wish him all the best for the future." Davis added: "We will confirm a successor in the coming months."

The move comes as the industry struggles under tougher gaming-machine regulations and online taxes.

The sector is also going through a period of consolidation that threatens the dominance of William Hill, which runs more than 2,300 UK betting shops.

Betfair and Paddy Power last year agreed to merge, online gambling business GVC bought rival Bwin.Party, and Ladbrokes and Gala Coral are also merging.

The sector is in the midst of costly upgrades to its online betting platforms, the fastest-growing sector of the industry.

In June 2016, shares in William Hill slumped to a three-year low, as investors increasingly fear the group is losing ground to rivals.

In May, William Hill said in a trading statement that its online sales were down by 11% in the 17 weeks to 26 April, due to "a disappointing Cheltenham Festival and unfavourable European football results".

The company maintains its full-year forecast for operating profits of between £260m ($343m, €312m) and £280m, compared with £291.4m the year before.