import re
text = "RECLAMADO: FOO LTDA - CNPJ: 99.999.999/9999-99\nRECLAMADO: FOO FOO LTDA - CNPJ: 99.999.999/9999-99\nTERCEIRO INTERESSADO: FOO FOO\nTERCEIRO INTERESSADO: FOO FOO FOO FOO - CNPJ: 99.999.999/9999-99\nTERCEIRO INTERESSADO: FOO FOO IT'S A TEST - CNPJ: 99.999.999/9999-99\nTERCEIRO INTERESSADO: TEST\nINTERESSADO: TEST - CNPJ: 99.999.999/9999-99"
print( re.findall(r'^(?!.*interessado: ).* CNPJ\W+(\d+\.\d+\.\d+\s?\/\d+-\s?\d+)', text, re.M | re.I) )
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