The company has started contacting agencies about the business, with chemistry meetings being held over the next week. A pitch will follow once a shortlist has been drawn up.
The DM review follows Opodo's appointment of Black Sun last month to handle its pan-European customer relationship marketing business.
Black Sun was appointed to help Opodo use its database to compete more effectively against online rivals such as Lastminute.com, Expedia and Cheap Holiday Deals.
Opodo has previously relied on weekly online campaigns involving e-mail newsletters, which were generated in-house.
Opodo is also seeking an agency to handle its £2 million European creative advertising account. In the UK, it has worked with Karmarama, which won the business from Leagas Delaney in 2004.
The online travel company, which is owned by nine of Europe's airlines, including British Airways, Air France, Alitalia and Iberia, offers access to more than 500 airlines, 65,000 hotels and 7,000 car rental locations worldwide.
The brand first launched in 2001 as a flight booking service. It rolled out in the UK in 2002 and has since added other travel products such as accommodation to its service.