With John now out of the Bangor fold, Robert Neill decided to make his other sons Charles and James partners with him. The Articles of Agreement were signed on 21 May 1866, and state how '…the said Robert Neill is now desirous of advancing his said sons in the world by taking them into partnership…' The papers that survive from these times prove that Robert Neill had wide financial interests, for besides the two local Gas Companies, he had shares in the Belfast Water Commissioners, the Co. Down Railway Company and the Belfast, Holywood and Bangor Railway Company. From the admittedly piecemeal evidence that exists, one receives some impression of a prudent and frugal man, thoroughly sensible in his investments, who is gradually amassing substantial wealth. It is perhaps a little surprising that his name is not among the nine Town Commissioners elected in 1864 under the terms of the Town Improvements (Ireland) Act of 1854, an important piece of reform which democratised the town. However, his son James was later to attain this honour.