Microsoft is to take on at least 400 Yahoo employees as part of the landmark search partnership deal announced by the two firms last week.
They agreed that an additional 150 Yahoo employees will assist in providing "transition services", according to documents published on Yahoo's website.
It has also emerged that Microsoft is to take on at least 400 other Yahoo employees and that Yahoo has built into the search deal two escape clauses.
Yahoo can walk away from the deal if the combined share of search queries falls below a set level, or if its revenue per search drops below a set percentage of Google's.
In addition, documents filed with the US Securities and Exchange Commission this week revealed that Microsoft will pay Yahoo $50m in each of the first three years of the 10-year deal to defray transition costs.
These payments are in on top of Yahoo's projected $275m annual income gains from the deal, which will see Microsoft take over the search technology for both companies.
Microsoft will also process the self-service adverts linked to specified search phases, while Yahoo will handle face-to-face sales of search adverts for both companies.