Business Stream has ambitions to make inroads into the English water market, which is undergoing liberalisation, while holding off competition from outsiders in its home patch.
According to accounts filed at Companies House, pre-tax profit at Business Stream rose by £2.5 million to £35.3m for the year to March 31 on revenue that was up 1.1% at £361.5m.
Chief executive Mark Powlis wrote in his report to the accounts that the company had produced a "solid set" of financial results.
"The competitive market in Scotland has now been open for five years. Over this time we have created a strong business that has delivered significant value for non-household customers."
He said that net cash inflow at the company had risen by 51% over the year and it is securing more customers onto long-term contracts.
Business Stream has also started to exercise long-held ambitions to enter the English water market. Earlier this year it revealed it had secured a three-year water supply deal to turkey giant Bernard Matthews' meat factory at Holton, in Suffolk,
Mr Powlis said: "Whilst we expect competitive pressures to increase going forward, we have crated a strong brand that is well positioned for long-term growth, as the Westminster Government brings forward legislation and reforms of the English market, creating a competitive model for one million non-household customers by 2017, similar to the market we have successfully created in Scotland.
This is a "real opportunity" for Business Stream, he added.
The remuneration of the highest-paid director, assumed to be Mr Powlis, came to £210,900, up 2.3% from £206,100.