Plus Markets, a UK stock exchange for small-cap companies, today said it hopes to break the Alternative Investment Market's trading monopoly by the end of this year, as it awaits approval from the UK financial regulator to offer transactions in all of the 1650 companies listed by its rival.

A spokesman for Plus said: "Originally HM Treasury raised this issue in February 2007 and we are still waiting for a rule change from the [Financial Services Authority]. Although we trade over 70 Aim stocks on Plus, which have been individually authorised, the bulk of the 1650 Aim stocks that we do not trade are effectively monopolised on the London Stock Exchange."