More than 100 failing academies have been removed from their sponsors and placed in new trusts, MPs have heard.
England's schools commissioner Sir David Carter told the Commons Education Committee 119 academies had been "re-brokered" as a last resort.
Some academies were performing no better than the failing schools from which they had taken over, he told MPs.
But he stressed the academies his team were most concerned about were being challenged and supported to improve.
Sir David said of the 973 functioning multi-academy trusts in England, only seven had been inspected by Ofsted as part of a process known as "batched inspections".
This is where a number of schools in an academy trust are inspected as a group because of concerns raised about performance.
Following these seven batched inspections, Ofsted reported concerns about the outcomes for pupils and accused some of the trusts of sitting on large sums of cash that should have been spent on pupils.
Sir David said: "There are academies that are performing not better or minimally better than the schools they were before. The commitment these sponsors made was to improve these schools rapidly."
Of the academies that had been re-brokered since September 2014, 68 had gone from a multi-academy trust to another multi-academy trust and 51 and gone from a single academy trust to a multi-academy trust, he said.
