British Library head of press and PR Greg Hayman said the remit would include both PA and media relations work.
'It's a mix of PR and public affairs and some high-level strategic press work to augment our existing press team efforts,' said Hayman.
'The brief is to raise awareness of our services to businesses among a range of key stakeholders,' he added.
The successful agency will focus on promoting the library's document supply business - a Yorkshire-based multi-million pound business, which supplies materials to research and development departments within corporates, including 91 of the FTSE 100 companies.
'That side of our work largely goes unrecognised and that's part of the task in terms of raising awareness,' said Hayman.
The British Library, which employs 1,100 staff in London and 1,300 in Yorkshire, is also looking to use the PR campaign to capitalise on the Government's recent pledge to give tax incentives to SMEs that invest in R&D.
There is currently no annually retained agency on the library's roster, but Hayman said two other agencies are working on projects. Arts and broadcast consultancy Anna Arthur PR is handling PR surrounding the library's Trading Places exhibition, while literary agency Coleman Getty is overseeing consumer PR for the Magic Pencil exhibition.