LONDON, Sept 6 (Reuters) - BlackRock, Fidelity, Legal & General, M&G and abrdn are among 125 firms endorsed under Britain"s tougher best practice code to stop "greenwashing" by asset managers, though 64 peers failed to make the grade, the Financial Reporting Council said on Monday. Asset managers are under greater scrutiny from securities regulators globally to prevent "greenwashing" or exaggerating the climate-friendly credentials of their products to investors. The FRC beefed up its decade-old stewardship code in 2020 to stop "boiler plate" statements about investment decision-making that it said did little to show if investors were getting value for money. The code is enforced on a comply or explain basis, meaning firms must say publicly why they are not applying it. The revised code says asset managers should not only spell out their actions in selecting investments, such as meetings with companies, voting at annual meetings, but also provide evidence on what the outcomes of those actions were, a step change. As Britain seeks to promote London as a global centre for sustainable investment, there is a strong emphasis on taking environmental, social and governance (ESG) factors into account when investing. The volume of money going into ESG products has risen significantly, raising fears among regulators of "greenwashing". All 300 asset managers who were signatories to the old code had to reapply, and the FRC said it received 189 applications, with an inability to provide proper evidence on outcomes a key reason why 64 firms failed to become signatories. The 125 signatories have a combined 20 trillion pounds ($27.7 trillion) under management, while the total for all 189 applicants was 32 trillion pounds. Several blue-chip names are not among the signatories but it is unclear if they applied. Some who failed to make the grade are expected to reapply in October, or April next year. "To remain signatories, organisations will need to continue to improve their reporting as market practice and expectations evolve," the FRC said. Firms that signed up to the code must state that on their website. $1 = 0.7230 pounds)