The appointment by Initial Style Conferences, which follows its sale to the Alternative Hotel Group by Rentokil Initial, includes the development of an ongoing communication strategy.
The launch campaign at the end of April will incorporate direct marketing, specialist press and online advertising.
Spinnaker will also develop ISC's new corporate identity, a move that marks the first stage of a complete brand overhaul.
Spinnaker has worked with ISC, which owns 29 properties nationwide, since 2004 running B2B email marketing campaigns.
This campaign will push ISC's new name, logo and positioning and will target corporate bookers of training courses, conferences and meetings including HR managers, PAs, trainers and agents.
As part of the corporate identity development, Spinnaker will be creating a corporate directory, in-room materials, in-venue materials, a website, site signage, stationary and POS materials.
David Owen, marketing manager at ISC, said: "Spinnaker impressed us with its passion, energy and outstanding creativity.
"This is an exciting time for Initial Style Conferences -- as brand guardians, Spinnaker will be responsible not only for the look and feel of the new brand at launch but also for all ongoing communications moving forward."
Brooke Dalton-Brewer, managing partner at Spinnaker, said: "We are delighted to be involved in such an exciting and challenging project -- our job will be to create an identity that not only talks to existing customers but which also invites customers who had previously overlooked the brand to look again."
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