Millennial travelers — defined as those between 18 and 30 years old — have different business and leisure travel habits and expectations than do their older peers, according to a global study by Expedia.com and Egencia, the business travel company of the Expedia Inc. group.

Conducted online across five continents by Harris Interactive, the Future of Travel study asked 8,535 employed adults in 24 countries about how they conduct business and leisure travel — their likes, dislikes and preferences. The study aims to discover how millennials will impact the travel landscape as they gain decision-making power at work and purchase power in their personal lives.

According to the study, differences emerged particularly in the differing value that younger travelers place on mobile and on loyalty. Millennials are more likely to embrace loyalty programs while en route — half of millennials find loyalty programs important when booking flights (48%) or hotels (51%) versus only three in ten of travelers aged 46-65 (31% & 30% respectively).

Mobile and other form factors are clearly important to the future of travel. In fact, for booking business travel, 32% of millennials report using a smartphone and 20% report booking on a tablet. That's compared to just 12% for smartphone and 9% for tablet for those over 45.

"Business travelers are early adopters of technology — millennial travelers even faster — and all on the move from device-to-device, from online to offline and back again," said Rob Greyber, president of Egencia. "We realize that keeping pace with millennials and future generations of corporate travelers demands significant focus on mobile in order to sustainably engage them with the right information."

According to the study, American and Canadian millennials travel more frequently of any age group across any nation, reporting that they take a full 7.8 leisure trips per year. On the contrary, European respondents aged 31-45 take 2.7 leisure trips per year.

"As millennials increase their decision-making power at work and at home, they'll be increasingly disruptive in both areas of travel, said Dara Khosrowshahi, chief executive officer of Expedia Inc. “And our aim is to have the right mix of technology, supply and programs to make the most of every trip they take."

Other key findings from the study:

• Millennials are more comfortable mixing business with pleasure: They are more likely to extend a business trip into a personal vacation than older employees — 62% of 18-30 year olds have done so versus 51% of 31-45 year olds and 37% of 46-65 year olds.

• Millennials are also more likely to voice their displeasure: 18-30 year old business travelers are the most likely to post a negative review online, as it relates to their experience with hotels, restaurants, flights, public transportation, taxis and rental cars. Americans under the age of 34 posted negative reviews of hotels (26%) within the last year, versus 14% of their older peers.

• Workers under the age of 45 tend to feel more entitled to their travel reward points than older employees: 83% of respondents worldwide feel that they should be personally entitled to travel reward points.

For more information on the Future of Travel Study, visit viewfinder.expedia.com.