Comms firm Maitland's The Values Most Valued By UK plc says that its research found 83 of the companies in the FTSE 100 declare a set of core values on their website or annual reports.
When it comes to what these values are, many companies state the same ones: integrity is claimed as a core value by 35 of the FTSE 100, respect by 29 and innovation by 24.
WPP and Royal Dutch Shell share exactly the same values of honesty, integrity and respect.
The study showed that Pearson is the only FTSE 100 company that has a unique set of values – bravery, imagination and decency.
Steve Marinker, head of Maitland’s corporate practice, said: "I’d urge businesses to think hard about values such as integrity, responsibility, transparency and trustworthiness.
"Most people will consider these to be universally desirable behaviours, rather than distinctive and informative glimpses into corporate culture."
Simon Walker, director general of the Institute of Directors, added: "In an era of radical transparency, driven by government and shareholder activism, businesses increasingly understand the need to give all their stakeholders an insight into the culture that governs their behaviours and decision making.
"The political landscape in this country is changing and the relationship between the public realm and private enterprise is back in the spotlight."