One of the world's largest operators of open-top sightseeing tours, Big Bus Tours, has hired JPMorgan to find a buyer in a deal that could value the travel firm at close to £500 million ($810 million), sources familiar with the situation said.

Big Bus Tours shareholders include the Maybury family, which founded TBBC in 1991 and Abu Dhabi-based Al Fahim Group, which acquired 30 per cent of TBBC in 2007.

The company's owners have appointed the US bank to lead a strategic review with a view to launching a sale process early next year, said one of the sources who could not be named because the matter is confidential.

Big Bus Tours was formed in 2011 by the merger of London-based The Big Bus Company (TBBC) and French peer Les Cars Rouges. At the time the merged entity had over 800 staff and a combined fleet of 300 open-top buses with more than two million customers each year.

Representatives of Big Bus Tours could not be reached for comment. Spokesmen for JPMorgan and Al Fahim Group declined to comment.

Big Bus Tours, which has become a familiar London presence with its burgundy and cream-coloured open-top buses, generates core earnings of around £50 million ($80 million). It could be valued at about $810 million given its global operations in 16 cities across three continents, two of the sources said.

The process remains in the early stages and prospective bidders have yet to receive initial briefing material, the sources said.

Private equity investors have so far shown appetite for travel assets particularly those combining travel operations and online booking services.

European buyout firms Permira and Ardian acquired online travel firm Opodo in 2011 for €450 million ($570 million), representing a multiple of 15.7 times its core earnings. At the time JPMorgan acted on behalf of Opodo.

The company was later merged with sector peers eDreams and Go Voyages to form Odigeo, one of the biggest online travel agencies.

European deals in the travel industry have hit a record $3.6 billion since the beginning of 2014, according to Thomson Reuters data. They climbed above US rankings which have so far totalled $1.1 billion of travel mergers & acquisitions (M&A) since January.

Big Bus Tours has worked hard on gaining scale in the United States and Asia since 2011. Its current portfolio includes open-top sightseeing tours in Hong Kong, Shanghai, New York, Las Vegas and San Francisco as well as in Middle Eastern cities such as Dubai and Abu Dhabi.-Reuters