The Organisation for Economic Cooperation and Development (OECD) has described the UK's academies as a "promising trend".
Andreas Schleicher, who is in charge of the Programme for International Student Assessment (Pisa), told MPs the best education systems combine local autonomy for schools with strong public accountability, the BBC reports.
He was speaking to the House of Commons Education Select Committee, which is currently conducting an inquiry into academies and free schools in England.
Local flexibility for schools is linked to higher results, he said - the world's most successful education systems feature "local discretion" for head teachers and school leaders combined with a shared expectation of high standards.
However, Mr Schleicher said autonomy needs to be balanced by a strong culture of transparency and accountability. He said evidence from the US suggests autonomy could be "part of the solution or else part of the problem".
"You need a very strong education system to make autonomy work, you can't leave it to market forces alone," he told MPs.
Mr Schleicher said children from disadvantaged backgrounds do not necessarily underperform academically and that the best systems have a culture of expecting good results from all pupils.
He praised the results of the London Challenge Initiative, which helped schools in the capital improve more quickly than anywhere else in the country.
Academies are now the most popular type of secondary school in England. Mr Schleicher was asked whether the creation of chains of academies undermined the benefits of local autonomy.
He replied that removing decision-making from individual schools could reduce the advantages gained by increasing autonomy.
The coordinator of the Pisa programme was also asked about the UK's performance in the latest Pisa rankings, in which the UK failed to improve.
He said the most successful education systems invest heavily in training and continuing professional development. This is evident in countries such as Finland and cities such as Shanghai, which require constant training and updating of heads' and teachers' skills.
Mr Schleicher defended comparisons between cities such as Shanghai and countries such as the UK, saying the city has a larger and poorer population than many OECD nations.
Posted by Theo Foulds