The pitch coincides with the appointment of Finsbury for financial PR, in a bid to build better relationships with the City as speculation mounts over a possible IPO.
Spirit head of communications Jill Rawlins said: 'We needed a financial agency to take us into the corporate and financial arena and create an understanding of who we are.'
She added: 'Spirit has tended to keep its head down in the past as it's concentrated on getting on with the business.'
Finsbury won the brief after a four-way competitive pitch, believed to have included Tulchan Communications and Cubitt Consulting.
Rawlins, who joined in October after seven years in the same role at retailer Somerfield, said the company was looking for a consumer agency with solid, regional media relations skills.
'A pub by its nature is your local, so we're looking for an agency to give us first-rate local coverage,' said Rawlins. 'We're yet to compile a shortlist, but I'm talking to a number of potential suppliers.'
Rawlins hopes to have a consumer agency on board by the end of next month.
The financial account is led by a three-strong team, headed by Finsbury partner Rupert Younger and associate partner Julius Duncan.
Parent group Punch, the UK's biggest pub company, is demerging both Spirit and sister firm Punch Pub Company.
It is widely believed Punch Pub Co will be the first to float. It is likely to be valued at around £2bn while Spirit is understood to be valued at £1bn.