Gateley is gearing up to become the first UK law firm to float on the London Stock Exchange, the firm has confirmed.

Capital markets investment bank Cantor Fitzgerald has been instructed by Gateley to work on a listing set to value the firm at around £130m to £140m, it is understood.

The Birmingham-based firm's plan is to join the junior AIM market, with an announcement expected within the next few months on the full details of the listing.

HBJ Gateley, the firm's Scottish arm and separate legal entity, is unlikely to be included in the listing, it is understood.

A Gateley spokesperson declined to comment on the initial public offering (IPO) except to confirm that the firm was "in the process of a listing".

Since 1 January last year Gateley has operated under an alternative business structure (ABS) licence. The licence allows the firm to raise a greater level of funding from outside the partnership.

However, at the time the licence was granted, senior partner Michael Ward said Gateley was primarily attracted to the ABS to allow non-solicitors to become partners at the firm as opposed to allowing a capital injection.

Reports earlier this year suggested that Irwin Mitchell had also appointed brokers to work on IPO plans first mooted as early as 2012. The firm would not confirm the appointment, however.

A spokesperson for Irwin Mitchell said the firm retained many corporate advisers and this was not unusual for any law firm.