Expedia.com, one of the world’s best known online travel agents, has announced that in celebration of the 40 years since the first Earth Day, it will be expanding its Green Hotel program. The program is aimed at travellers who wish to place the environment high up on their list of priorities when it comes to choosing a hotel.

The program features a list of more than 1,700 hotels, all of which have been certified as being ‘green’ by a number of organisations including STEP, LEEDS, Green Key and Green Seal. Expedia.com’s Green Hotel program was set up in April 2008. It has quickly grown, and this year has a list of partners which is six times longer than it was last year.

As well as having more than 1,700 hotels, the program also relies on more than 80 certification programs which are used to asses the individual hotel’s environmental sustainability.

Tim MacDonald, Expedia.com’s senior vice president and general manager, said that he realised that being able to provide means of green travel to customers was extremely important. He said that Expedia.com was now able to offer a one-stop-shop for customers wishing to travel in the most environmentally friendly way possible.

As well as offering green hotels which have been assessed by respected bodies in the travel industry, Expedia.com also offers customers the chance to offset their carbon on flights, as well as access to advice on how to travel sustainably. Expedia.com also offers large savings for customers who decide to book a green package through the site.