ðə tˈuː kˈʌmpəniz wˌɪtʃ kˈeɪm tə dˈɑːmᵻnˌeɪt ðə dˈɪstɹɪkt wɜː kˌælɪdˈoʊniən kˈɑːlɪɚɹiz lˈɪmɪɾᵻd, ænd dʒˈeɪ ænd ɐ bɹˈaʊn ænd ˌæbɚmˈeɪnsˈiːhæm kˈɑːlɪɚɹiz lˈɪmɪɾᵻd ɐ mˈɜːdʒɚɹ ʌv θɹˈiː fˈɔːɹmɚli sˈɛpɹət kˈʌmpəniz.
The two companies which came to dominate the district were Caledonian Collieries Limited, and J & A Brown & Abermain-Seaham Collieries Limited (a merger of three formerly separate companies).