BFI head of press and PR Judy Wells said that as a public sector government body, the BFI was required to re-tender its supplier contracts regularly.
The work is now being split into two contracts because of the recent growth of the London Film Festival, which is taking place in October at various locations throughout the capital, Wells said.
BFI is also creating a dedicated six-month in-house PR role, focusing on the festival, with the successful applicant expected to start in May, Wells added.
Each contract will be awarded for an initial period of one year, and each has an option to extend for up to four additional years.
The fee will be paid on a monthly basis for both contracts, which translates to approximately £21,000 per month, but the BFI said this payment schedule is up for negotiation.
The first contract, worth an estimated value of £700,000 over five years, includes working alongside the BFI press office and festival team to manage and deliver PR and publicity across all media platforms, incorporating consumer and trade media.
The second contract, worth an estimated value of £550,000 over five years, includes work on BFI's headline gala and special presentation screenings, which take place at Odeon cinema on Leicester Square during the opening and closing night of the two-week festival.
The successful agency will be expected to work alongside the BFI PR, social media and marketing teams and the festival team to manage and deliver effective PR and publicity across all media platforms, BFI said.
"Agencies are invited to tender for both contracts if they have the requisite skills and resource," Wells said.
However, she advised that any agency considering pitching for the business should have experience of the film industry and the "cultural landscape".
Interested parties can submit proposals until Monday 13 March, when the tender process closes.
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