The call by the ECTA, which represents new entrants to the industry and internet service providers, could increase pressure on telecoms firms hostile to a tentative proposal by the EU's telecoms chief to cut the fees they charge rivals to use their copper-based networks.
"European consumers and competitors should not have to pay excessive prices to dominant operators," ECTA Chairman Tom Ruhan said in a statement.
"It must be made clear that dominant operators that receive excess profits from their legacy networks paid by their customers should pay the money back by reducing charges on high-speed fiber networks," he said.
Ruhan said another option was to channel the money into a fund available for other potential investors in open fiber networks.
Former state-owned telecoms operators such as Deutsche Telekom AG (DTEGn.DE), Telefonica SA (TEF.MC), France Telecom SA (FTE.PA) and Telecom Italia SpA (TLIT.MI) inherited copper-based networks when they were privatized in the 1990s.
EU Telecoms Commissioner Neelie Kroes said last month operators were too comfortable with their old systems and had little interest in spending heavily to install fibre networks.
She reiterated on Monday that she was looking at price cuts.
"We are exploring whether copper prices could be gradually adjusted after a certain time," Kroes said in a speech to be delivered at an ECTA conference in Brussels.
She said increasing broadband penetration across the 27-country European Union by 10 percentage points could boost growth by 0.9 percent to 1.5 percent.
Telecom Italia Chief Executive Franco Bernabe has criticized Kroes' idea as "simply crazy."