As some questions came up about the Caldera Mining Company on Discord, I decided to do my homework for once and sift through the source material. I might still have missed something or gotten something wrong, so please do correct me where you see an error.
The first question is whether there is any link between the East Empire Company and the Caldera Mining Company. I couldn't find any suggestion of such a link, and there are a few things that would suggest a link doesn't exist. In-game dialogue says that the EEC "has sole authority to trade in certain goods, like flin, raw ebony, raw glass, and Dwemer artifacts". But that's 'trade'. The Hlaalu quest Epony Trade concerns the EEC being dissatisfied with Hlaalu ebony prices and seeking deals with Redoran mines instead, which would be strange if the CMC were a direct subsidiary of the EEC. "The raw ebony deposits here on Vvardenfell are the richest in the world. And the deposit in Caldera is the biggest on Vvardenfell." That suggests that the EEC has to buy the ebony from the houses that oversee ebony extraction and trade it on from there, rather than being involved in extraction themselves.
As far as I can see, the EEC never comes up in the quests dealing with the Caldera Ebony Mine, despite all the digging by the player and others to uncover the workings of the operation. Importantly for us, it does not look as though (at the very least in this instance) the EEC is in bed with House Hlaalu; while not straight rivals, their relationship appears to be frosty. While the in-game East Empire Company faction has +2 relationship with House Hlaalu, it was only added by Bloodmoon and Hlaalu has no relationship value for the EEC, so that seems like it might be a minor instance of Bethesda fumbling the ball.
While House Hlaalu oversees the Ebony extraction in Caldera and apparently is the one to sell the ebony on, the CMC is the one extracting it. So the second question is what the relationship between Hlaalu and the Caldera Mining Company is. Cunius Pelelius is "a principal and charter-holder of the Caldera Mining Company", and for the purposes of the game he is the one in charge of the Caldera Mining Company. He is also a Lawman of House Hlaalu. He is not, however, the sole owner: "Cunius Pelelius is a part of the trust who received the exclusive Imperial charter to exploit the rich ebony deposits of Caldera Mine". He appears to be 'a' charter holder rather than 'the' charter holder; the others might well be back in Cyrodiil though we could consider having some on the mainland as well.
Dialogue -- both from Hlaalu characters and non-Hlaalu -- is quite consistent in stating that Hlaalu does not control the charter directly:
House Redoran is really steamed up about the Caldera land grab. They say that Caldera is in their territory, and that they should have gotten the charter. Worse yet, they say that Hlaalu is skimming the top off the Imperial fatcat company that got the charter. Since it's an Imperial company, Redoran can't even get a House War contract on it.
House Hlaalu would much rather have the Caldera charter, thank you very much, and run those ebony mines ourselves. But it hasn't worked out so badly. The Imperial Caldera Mining Company is laying out the cash and doing the work, and we're talking the cream off the top in graft and bribes.
And how do you think it was that bloated Imperial plutocrats got the charter to exploit the Caldera ebony deposits, and not a native Great House or local colonist? Big fat bribes, I tell you. And friends in high places.
These lines seem to make it clear that the charter holders are, taken as a whole, neither local colonists nor Hlaalu.
The exception is Garisa Llethri, who associates the operation directly with House Hlaalu: "Since the mines are run by the dishonorable House Hlaalu and the Empire, I am sure there is corruption." "Yes, killing the head slave Dahleena will make the Hlaalu's mining more difficult. Good slaves are so hard to find these days... I expect the Hlaalu will not resume mining for at least a month." Given that otherwise both Hlaalu and non-Hlaalu are consistent in saying the mines aren't directly controlled by Hlaalu, it seems more like Llethri's being inaccurate as he sees House Hlaalu as his rival rather than an Imperial company.
While it's clear the CMC is very much in bed with House Hlaalu, it does seem to be set up as an Imperial company with its own Imperial charter, not formally owned or controlled by anyone except the charter-holders, at least one of whom happens to be a member of House Hlaalu, but with enough plausible deniability to remain an Imperial company. As such, it does work as a reference for similar charter companies like the ZBC. The stated role of Cunius Pelelius, 'principal', could be used for other charter companies. The role 'director' has also been suggested, and is used by the East Empire Company: "The East Empire Company is a monopolistic mercantile enterprise chartered by the Emperor and managed by a board of directors appointed by the Emperor."
