Research by the industry body found the number of FTSE 100 and 250 companies issuing quarterly reports since October 2016 has declined by 19% and 25%, respectively.
Furthermore, more than 40% of FTSE 100 and 60% of FTSE 250 companies no longer issue quarterly reports to shareholders, the IA found.
It heralded the findings as evidence that its call for an end to quarterly reporting is being heeded by the UK’s largest companies.
This comes after the IA published a wider Productivity Action Plan in March 2016 which calls on companies to stop issuing quarterly reports and earnings guidance, and to publish Long Term Reporting Guidance, which sets out guidelines for company reporting on productivity, capital allocation and culture.
It also involves the creation of a Stewardship Reporting Framework to assist asset managers on reporting their stewardship activities.
The IA said 18 months since its launch, it has completed more than half the recommendations set out for the asset management industry in 2016 and is on track to complete the remaining actions by 2019.
Chris Cummings, chief executive of the IA, said: “The UK’s productivity puzzle is one of the biggest challenges of our generation. Solving it is crucial to closing the gap with our major international rivals and to helping the UK become more competitive on the global stage.
“Stronger, more productive businesses are more likely to deliver the long-term investment returns for the millions of people whose savings and investments are managed by our industry.”