In Germany, there are "Genossenschaften"[1], which are cooperatives organized by small members to further a common commercial interest. For example, winemakers, which are often family businesses (at least in the area I'm from), often form them to sell wine, to have better leverage against the buyers, which are usually big companies like Aldi.

[1]: https://en.wikipedia.org/wiki/Eingetragene_Genossenschaft

I believe this would be illegal under price fixing laws in many countries.

Multiple companies colluding to set certain terms on sales is illegal in many places.

They have these in the U.S. Chambers of Commerce and industry organizations, especially lobbying groups, are numerous.

In the Netherlands dairy farmers formed their own cooperative so sell dairy products to prevent 3rd party 'big dairy' corporations from playing them against each other on price and quality.

https://en.wikipedia.org/wiki/FrieslandCampina

Practically all unions in Norway work that way. Benefit of not having the union tied to the employers:

- Large and resourceful union even for employees in small companies.

- Not too tight with any particular company, helps keep the workers rights in focus

- Continuity when switching employeers

As other have noted, guilds, especially around movie and television production. The WGA, SAG-AFTRA, DGA, PGA, are some examples. There are some newspaper specific guilds, though some of them are part of the CWA or other affiliate unions.

And of course, some of those guilds have a choice in contract types, staff or freelance. The WGAE, where I was a member and part of the negotiating committee for my then-employer, had its own CBA for our “shop” — but the WGA and WGAE also have MBAs (minimum bargaining agreements) for freelancers, which is the more traditional model for entertainment guilds (though WGAE in particular has shifted a lot of its attentions to staff contracts).

Yes. Cooperatives. Farmer cooperatives are quite common for example. Basically, freelancers who have to negotiate with the same small number of other entities can form a cooperative to both handle the admin and also allow them to negotiate as one.

Producer coops are common in the USA part of KFC is one I seem to recall.

Worker coop is quite different - having been a member of one in the UK - I Know one UK union looked at forming a coop to get round IR35

It's that pretty normal? That's what unions generally are, or am I misunderstanding your question. Denmark have/had unions for "office workers", engineers in general, steel workers and more. They are in the same industry, mostly, but they don't work for the same company.

The members of these unions are generally unrelated, they just have jobs in the same sector of industry or very similar education.

I think the weird part is when a union just represent the people working for one particular company.

Screen Actors Guild

"Trade association" would be the more common term for business owners.

"Guild" might not go down to well in the USA as it sadly implies restrictive practices (descrimation against black workers) - read up on the early labour history in the USA.

Guilds?

Yeah, a pretty big one: craft guilds.

And sometimes the guild took the reins from the the state! https://en.wikipedia.org/wiki/Hanseatic_League

Say what you will about (proto-)mercantilism vs capitalism, but I rather live under guild-ocracy then cyberpunk megacrop-ocracy.