If I want to say that a holding company owns and operates a number of oil-processing plants, all interlinked in the business sense but spread across different locations, what words/phrases could I use? In Russian, we use the word *complex*, like *complex of oil-processing plants*, but in English *complex* seem to imply the presence of its elements at a single location or their physical connection (*complex of roads*), but not their connection in the sense of product streams. 

Am I right that "complex of plants" or even "complex of enterprises" (as one Russian dictionary suggests) will sound and look strange to a native speaker? 

I looked for synonyms and found "system, network". Are these O.K. and what other words/phrases could be used to the same effect?

> 
> "According to the plan, the Holding's **network/system** of oil processing
>  plants will process some 8 mn tonnes of crude next year."
> 
> 
>