Pauley left after his request to become chief executive of the agency was refused, a source told PRWeek. He declined to comment on the subject of his leaving the agency and setting up his own business, but refuted that he had left after his request to become chief executive of the agency was refused, telling PRWeek this was "not accurate".
His role at Portland included advising FMCG and financial services brands, and worked across regulated sectors including energy, water and telecoms.
He also has experience of crisis and issues management including restructure, M&A and product recall, and has worked on major Government procurements.
A senior industry source told PRWeek that Pauley would be likely to take several clients with him as he left the agency.
The source added: "Pauley is low-profile within the industry but has played a huge part in Portland’s rise to success. His departure will have a massive impact on Portland’s future success."
Tim Allen, managing director at Portland, said: "I've really enjoyed working with Oliver and I wish him the very best for the future."
The majority of Portland's staff are in its London HQ, but it also has offices in New York, Washington DC, Doha, Nairobi and recent opening Singapore.