Despite competitive pricing from rival firms, RNS held firm at 71 per cent share of the regulatory announcements market, said the report by Knowledge Technology Solutions (KTS).
RNS's monopoly on regulatory announcements ended in 2002, leading to steady erosion of its share of the market as the UK's biggest primary information provider (PIP).
But the six months between August 2004 and last month saw the second largest PIP, PR Newswire's market share decline from 11.8 per cent to 11 per cent. BusinessWire, the fourth-largest PIP, fell from 7.7 per cent to 7.4 per cent.
The only significant gainer was Romeike (formerly Waymaker), which handled 9.2 per cent of regulatory announcements, up from 8.3 per cent.
KTS MD Marc Pinter-Krainer said RNS's resilience to competition had put pressure on other PIPs to 'rejig their prices'.