Some schools are still missing their test results
Exam board Edexcel has been given a contract to provide "back-room" support for the remarking of England's national test (Sats) papers.
Many papers are being reassessed after complaints about the quality of this year's marking, which had been handled by ETS Europe.
Problems led to continuing delays in results, with 5% of papers for 14-year-olds still outstanding.
Edexcel managed the Sats tests and marking between 2004 and 2007.
The five-year contract between ETS Europe and England's exams regulator, the Qualifications Curriculum Authority (QCA), was scrapped nearly two weeks ago.
It was the first year that the American-backed firm had handled the tests, taken by England's 11- and 14-year-olds in English, maths and science.
The National Assessment Agency (NAA) took over the management of appeals and remarking from ETS in July.
It said Edexcel had been contracted to provide "additional back office support" to complete the reviews process.
This would involve "logistical and managerial support and data entry facilities", the NAA said.
David Gee, managing director of NAA, said: "Following the delays and data entry problems experienced earlier this year, it is vital that the reviews process is robust, effective and retains the confidence of schools in the outcomes of the tests.
"I am pleased that Edexcel are assisting us in this work. The quality measures put in place this year gave a greater number of checks on markers' adherence to the mark scheme.
"However, if schools have evidence that the mark scheme has been misapplied, they should apply for a review, and the NAA will ensure the application is properly evaluated and, where necessary, scripts remarked."
Jerry Jarvis, managing director of Edexcel, said: "Many thousands of students have worked exceptionally hard towards their key stage tests.
"It is crucial that teachers, and students and their parents, have faith in the outcomes of students' work.
"We are pleased to be able to assist NAA by applying the management, logistical and systems expertise and resources of our organisation to ensure that pupils get the results they deserve this year."
ETS's £156m contract was dissolved earlier this month by "mutual consent".
The company was ordered to pay back £19.5m to the QCA plus £4.6m for the cancellation of invoices and other charges - more than two-thirds of the money paid out for the 2008 tests.
The QCA has not revealed how much the contract with Edexcel for the review process is worth.
A spokesman said the financial arrangements of the contract were based on the volume of scripts processed for review and remarking, plus an associated management fee.
An inquiry into the problems with this year's Sats marking is being led by Lord Sutherland. A report is due in October.
Schools have until September 10 - or 10 days after they return - to appeal against the marking of Sats papers.