An amicable agreement had been reached as a pay out for the final year of his contact, the federation said in a press statement.
Ferrin accepted four months’ pay, to the value of $120,000, as compensation for the final year of his contract.
In December, Ferrin failed to travel with his squad for the start of their Africa Cup of Nations preparations because of a dispute over his unpaid salary, but the problem was later resolved.
He took over as Angola coach in July last year and won two of 10 matches in charge.