"Formal negotiations" refers to a structured and serious process where people discuss and make agreements or deals, typically in a business or diplomatic context. Full definition
The contest has to be seen as a worthwhile effort, given the lack of meaningful results from nearly 20 years of formal negotiations. (dotearth.blogs.nytimes.com)
Galatasaray said they had begun formal negotiations with both club and player over a deal that could cost around # 6 million. (espn.in)
In Bonn, we will be pressing negotiators to back the launch of formal negotiations on a global HFC phase - down under the Montreal Protocol at the upcoming Meeting of the Parties in Paris in November. (eia-global.org)