Airberlin had an "bankruptcy self managed" that means they filed bankruptcy but had an own guy taking care of it, and by this they needed money from the government (150Mio €) and were able to continue trading/ dealing to split up everything. The 150€ from the government saved the salaries for 3 months so the airline wasn't grounded. Reason for this were the expensive slots and other stuff. They now managed to pay back all 150mio€. Slots were not lost, and were traded.
but I don't see a reason why LH should by Condor. There is Thomas Cook Aviation (old new subsidiary Airberlin aviation 2.AOC) which is operating a lot cheaper with a modern 321sharklet harmonized fleet. If Lufthansa buys, then that airline with slots!