The company plans to appoint three agencies by September to handle its creative, digital and consumer PR briefs.
The work up for grabs relates to its 2009/10 brand awareness and sales campaign. The agencies will be briefed to work alongside the company's in-house marketing team.
Unite decided to create the roster following a review of its marketing needs and several staff appointments and promotions.
Its properties house about 38,000 students across the UK in 30 cities, such as London, Leeds, Glasgow, Birmingham and Cardiff.
The company also has a range of affiliate marketing partners including Domino's Pizza, Play.com and Endsleigh Insurance.
The partnerships involve the provision of special deals for students, such as discounts on pizza. It has an exclusive relationship with BT, which provides broadband for its student rooms.
Recently, Unite debuted Livocity, a more upmarket accommodation brand, intended for post-graduates.
Founded in Bristol, Unite now has regional offices in London, Salford, Edinburgh and Newcastle.
There are currently more than 2.2m higher education students in the UK. According to Unite, the student-housing market is worth more than £46m.