Complex sentence: At the end of the 1950s, Carrick's owned more than 100 outlets but Low Row had ceased to be a dairy: waitress service was becoming the exception and Carrick's management model was outdated and losing ground to local energetic competitors such as Greggs of Gosforth.
Split into simpler sentences: At the end of the 1950s, Carrick's owned more than 100 outlets but Low Row had ceased to be a dairy. However waitress service was becoming the exception and Carrick's management model was outdated and losing ground to local competitors such as Greggs of Gosforth.