German reservations include how to safeguard jobs and protect the merged firm from any future hostile takeover, a government document obtained by Reuters on Monday showed.
On Wednesday, a French government source said France would want to retain certain rights, as well.
EADS is standing firm, reiterating its “intention and current expectation” to provide further clarity by that date.
Technically, extensions to the UK stock market deadline are relatively simple and are usually granted, lawyers say.
Yet in classic European negotiating style, as seen on issues from farm subsidies to national bailouts, talks generally go down to the wire.
Raising the threat of a missed deadline, or demanding it be kept, is a tried and tested tactic in the brinkmanship so often seen among the 27 nations of the European Union.
De Maiziere called talks with his British and French counterparts on Wednesday evening “constructive”.
“This is a complex situation, there are a lot of questions and conditions, nothing has (been) decided yet ... We will keep in contact,” he said.
European governments all face severe spending pressures, but a stand-off between France and Germany over control of EADS is seen as the bigger roadblock, rekindling a climate of mistrust which set in during management rows from 2005 onwards.