The U.S. Justice Department has given its approval to the sale of Reed Elsevier’s Harcourt U.S. education business to HM Riverdeep, the corporate parent of Houghton Mifflin. The DOJ put no conditions on the sale, such as the sale of some assets, as some industry observers as thought. The deal, first announced this summer, includes Harcourt’s elementary school publishing businesses as well as Harcourt Trade.

The move clears the way for the $4 billion deal to be completed soon, although the exact timetable is unclear. In its announcement, Reed said the transaction will close in mid-December, but the Irish newspaper The Independent, reported that the three banks that are underwriting the purchase are not expected to complete putting together its financial package to early next year. Barry O’Callaghan, who controls HM Riverdeep, is based in Ireland.