German maintenance specialist Nayak and logistics group Zeitfracht will jointly acquire Air Berlin's technical operations.
Air Berlin says its creditors have accepted a proposal for the sale, and that a contract is set to be signed this week.
No financial details have been disclosed.
Under the deal, the buyers will take on "at least" 300 of Air Berlin Technik's approximately 850 employees, the insolvent Oneworld carrier says.
Air Berlin Technik has facilities in the German capital, Dusseldorf and Munich.
For the remaining staff members, the parties arranged establishment of a transfer entity in order to "cushion social hardship", notes Air Berlin.
The transfer entity for Air Berlin Technik staff will be financed without state or third-party support as a result of the "liquidity situation in this process", the carrier adds.
Air Berlin disclosed on 24 October a plan to fund a similar entity for its airline employees, provided that other partners involved in the insolvency proceedings contribute to the effort.
Meanwhile, Berlin's regional government has signalled its support for a fund to cover the airline's ground personnel.
Zeitfracht will acquire Air Berlin's cargo operations under a previously disclosed deal.