UK fund manager Richard Buxton has been liaising with the Financial Reporting Council (FPC) on its new corporate governance rules for UK companies.
The Merian Global Investors fund manager said companies tended to focus too much on shareholders at the expense of other stakeholders.
This is why he contributed to the FRC's consultation on the matter last year, which led to a new code being published last July, effective from this year.
The new code requires firms to take a wider approach and to take into account the purpose of the business and other stakeholders.
In particular, the rules, which are not mandatory but require firms to declare why they opt not to stick to them, ask firms to operate with the interests of employees, customers and the wider community in mind.
Mr Buxton said: "I have made the point for a long time that while Article 172 of the Companies Act states that companies must act in a way that maximises shareholder value, while taking into account other stakeholders and wider society, whenever I speak with company management, they tell me they focus only on the first bit of that, on maximising shareholder value, and ignore the wider impacts.
"But the new code, it will be quite revolutionary, it will require firms to have a purpose and to be able to evidence how they are taking into account the other stakeholders, not just the shareholders. This is a generational change that will improve governance."
Under the rules, all companies listed on the London Stock Exchange must show in their annual report and accounts how they have complied with the rules.
The FRC divided the code into four sections: board leadership and company purpose; division of responsibilities; composition, succession planning and evaluation of board members; audit risk and internal controls and remuneration at board level.
When announcing the new code, the FRC stated: "[The code] places greater emphasis on relationships between companies, shareholders and stakeholders.
"It also promotes the importance of establishing a corporate culture that is aligned with the company purpose, business strategy, promotes integrity and values diversity."
In addition to his role as manager of the Merian Global Investors UK Alpha fund, Mr Buxton is also a board member, shareholder and head of UK equities at Merian, having been part of the management team since it teamed up with a private equity firm to buy the business from parent company Old Mutual.
Merian Global Investors has a majority of women on its executive committee.
Meanwhile Mr Buxton described Brexit as a "handbrake" on the UK economy, but added that he doesn’t believe a recession is imminent due to the continued strength of the labour market, with there presently being 800,000 job vacancies in the UK.
He added: "Brexit has only really negatively impacted the economy over the past six to nine months."