ETA, formerly known as Ebauches SA, is a Swatch-owned company producing watch movements and components. Formed in 1921, it's a conglomerate of formerly independent brands such as Valjoux, Unitas, Felsa, Venus, A. Schild, Landeron, Peseux, Fleurier, Eterna, Reymond, Cyma, Gruen, Ernest Borel, Doxa, Cyma, Certina, Edox, Eterna, Mido, Oris, Angélus, Excelsior, Universal, Movado, Longines, Record, Rotary, and others... Quite the list, eh?
Repeatedly investigated for monopoly pricing and allocation of movements, their behaviour is widely disliked. (And another!) However, their movements are first rate and used in nearly every watch company producing mechanical watches. In modified form, e.g. with Dupois-Dupraz modules or co-axial escapements, they inhabit such brands as Omega and Ulysse Nardin.
From this page on Unitas (one of the subsumed brands)
Ebauches SA had been formed in 1926 in Neuchatel as a holding company that brought together Switzerland's largest ebauche firms, which included Valjoux S.A., ETA S.A., Felsa S.A., Venus S.A. and others. Fabrique d'Ebauches Unitas S.A. joined this confederation in 1932. Ebauches SA proved vital to the survival of the ebauche industry in Switzerland.