Highlighting the prospect of rapid growth in demand for the sophisticated meters the firms supply, Mr Bellamy-Lee said: "I think there's enough space in the market for both of our companies to operate."
Energy Assets and Smart Metering Systems have both majored on the industrial and commercial gas meter market.
Mr Bellamy-Lee was speaking after Energy Assets revealed it grew profits before tax and exceptionals by 72%, to £6.7m, in the year to March, from £3.9m in the preceding year.
Energy Assets said it is on track to deliver another strong performance after making a good start to the current year.
The company highlighted the benefits it expects to enjoy as a result of the £2.3m acquisition of Lancashire-based Bglobal Metering in April.
This took the gas specialist into the electricity meter market.
Mr Bellamy-Lee said further acquisitions could feature as it looks to maintain growth. He said the company had nothing to talk about currently.
Energy Assets had £47m cash and borrowing facilities in place at 31 March, which it could draw on to fund expansion.
Chief financial officer John McMorrow said: "There is a wealth of opportunity to grow organically from the size of the market."
Energy Assets owned 86,000 industrial and commercial meters at 31 March.
It reckons there are 1,500,000 I&C meter points in the UK.
Energy Assets also had 15,000 domestic meters at the year end.
The size of the market should grow rapidly as suppliers move to fit smart meters to comply with regulatory changes that are intended to boost energy efficiency and reduce carbon emissions. All industrial and domestic gas meters must be smart or advanced by 2020.
Mr Bellamy-Lee said Energy Assets had built a business that could be scaled up profitably.
The company increased underlying earnings before interest, tax, depreciation and amortisation by 39% to £15.0m in the year to March, from £10.8m last year.
Mr Bellamy-Lee said the company had maintained margins. Revenues increased by 34% annually, to £24.2m, from £18m last time.
Energy Assets has around 161,000 meters following the Bglobal acquisition.
Mr McMorrow noted that recurring revenue represented 70% of the total income in the latest year. He said this meant there was a high degree of visibility about future revenues.
Analysts at house broker Numis Securities told clients: "We remain positive on the long-term outlook for the business as it continues to build its asset portfolio, which provides long-term, highly visible cash flow, with new customer contracts."
Shares in Energy Assets closed up 7%, 23.5p, at 348.5p.
Led by chief executive Alan Foy, Smart Metering Systems grew profits before tax and exceptionals by 20% to £7.7m in the year to December, from £6.5m in the preceding year.
The company bought the Utility Partnership electricity meter business for £14m in April.
Asked about Energy Assets' remarks, a spokesperson for Smart Metering Systems said the company had no comment to make.