The publisher would not specify which titles would be affected by the redundancies.
A spokesperson for RBI UK said: "While we regret the loss of any employee and always seek alternatives to enforced redundancies, these changes are guided by the long-term structural needs of our business and are also necessary for us to remain competitive in the face of an increasingly challenging marketplace.
"We will support impacted employees during the coming weeks as they pursue opportunities both inside and outside the company, providing them with competitive severance benefits and career transition assistance throughout their redundancy consultation periods."
Reports in the US claim that RBI is making 7% of its workforce redundant.
Sara Nelson, the editor of Publishers Weekly, is among the most high-profile executives to be axed.
The downsizing comes less than two months after Reed Elsevier, RBI's parent company, ended its bid to sell RBI amid poor market conditions.
Reed Elsevier announced its intention to sell RBI in February last year, claiming that its ad revenue model no longer fit the subscription-based model of Reed Elsevier.
Later, the Anglo-Dutch group said it would be willing to provide financial support for a successful bid for the unit, which fell in value from an estimated £1.3bn when the sale was announced, to between £650m and £850m.
But Reed Elsevier pulled the sale altogether in December, saying at the time that it was "not possible to structure a transaction on acceptable terms" due to the economic downturn.