Councils are best when it comes to boosting the inspection grades of inadequate schools, analysis of official figures suggests.
Researchers looked at how much schools rated inadequate by Ofsted in 2013 had improved by the end of 2017.
Those schools that had remained council maintained were more likely to be good or outstanding than those that had become sponsored academies.
The government says academy status helps schools raise standards.
But the Local Government Association, said the research, which it commissioned, "clearly demonstrates the excellent track records councils have in turning round failing schools".
Under changes introduced in 2016, all schools rated inadequate by Ofsted must now become "sponsor-led academies", which means being taken over by an academy chain or multi-academy trust and no longer being maintained by their local authority.
Of these, they found 152 had stayed with their local authority and 212 had become sponsored academies. Most of the remaining 65 either closed or were taken over by other schools.
By December 2017:
- All 152 of the local authority schools had been re-inspected and 115 (75%) were rated good or outstanding
- Of the 212 sponsored academies, 155 had been re-inspected, of these just 92 (59.4%) were rated good or outstanding
The Local Government Association, which is holding its annual conference in Birmingham this week, says the figures reinforce calls for the bar on councils intervening in struggling schools to be overturned.
In a paper published on Thursday, local authorities argue that they should have a role in improving all schools found to be inadequate, whether maintained or academy schools.
"Underperforming schools are more likely to improve when supported by their local council than by an academy sponsor.
"In all areas of the country, maintained schools outperform academies," says the report.
The LGA points out that councils have a duty to ensure all children and young people get a good education - but the current rules mean they have limited powers to hold academies to account for their standards.
Roy Perry, vice-chairman of the LGA's Children and Young People Board, said the new figures clearly demonstrated "the compelling need for councils to be recognised as effective education improvement partners, ready and able to support schools of all types".
"It is not fair on children and parents to be denied the chance of a better education because their local council, with expertise in school improvement, is barred from helping," said Mr Perry.
A Department for Education spokeswoman said: "These calculations are misleading and fail to take into account that every school will have individual challenges, some of which, such as poor leadership and management, are far greater and taken longer to turn around, than others.
"Placing schools back under local authority control would be a backwards step and would not necessarily deliver the improvements in education children deserve."