Like Fusion Centers of the Department of Homeland Defense, the United States has centers called ISACs (Information Sharing and Analysis Centers) which collate data from American industries, look for threats, patterns and anomalies, and will link this data to the intelligence community and classified information. A Google search for "ISAC information sharing" will get you information on these.
ISACs are public-private enterprises. Onboarding to information sharing programs are not required by law, but some of them are required if the corporation is going to handle government business. Due to its public-private nature, it is bound in some cases by private restrictions and in others by public restrictions - but in general enjoys the freedom of being able to work without the full limitations of others.
There's a great talk (there is also a video somewhere...) of information sharing initiatives, policy, investments and brainstorming of solutions to problems ranging from the technical to the regulatory.
At approximately 1:14:00 (though you may want to start a couple minutes earlier) you can hear the ISAC director discuss how important it is for corporations to understand that the US government will not use any information used by these programs for legal purposes.
Googling for "company information shared network cannot legally" wasn't very productive.