Cenkos Securities Plc's fifth largest shareholder, Crystal Amber Fund Ltd., wrote to the London-based broker seeking a "strategic review to determine how value can best be realized," Sky News reported, citing the letter.

The Richard Bernstein-led activist fund expressed concern about Cenkos' franchise struggling to create "a broader, more recurring revenue base," but said the company's existing platform could be "an attractive springboard for a larger financial institution." The letter, addressed to Cenkos Chairman Gerry Aherne, was written earlier this month, according to the report.

In a July 24 trading update, the broker said it expects revenues for full year 2018 to be "materially below" levels seen for the previous year.