Herbert Smith Freehills (HSF) has topped the latest ranking of firms by their share of the UK listed company market, pushing Slaughter and May into second place for the first time in eight years.

The rankings, published by Adviser Rankings in association with audit and advisory firm Crowe Clark Whitehill, place HSF at the top of the overall table, after the firm added 12 listed clients to take its total to 109.

The additions for HSF and the change at the top of the table come after Adviser Rankings changed its ranking criteria to include companies listed on the Specialist Fund segment of the London Stock Exchange for the first time.

This decision added 35 companies to its adviser rankings, 10 of which name HSF as adviser. The additions for HSF include UK healthcare bond fund BioPharma Credit, Sherborne Investors – the vehicle of New York-based activist investor Edward Bramson – and aircraft leasing and acquisition investment company Amedeo Air Four Plus.

The firm came third in the FTSE 250 rankings and fifth in the FTSE 100 table (see below for these tables).

HSF London corporate head Ben Ward said: "Obviously this league table has been around for a while. We're always highly ranked and we've always had a strong relationship with listed companies. Investment funds have recently been admitted. They are listed companies which require advice, and it is often complex. They are important clients and they play a major part in the London listed market."

The shift in criteria knocked Slaughters into second place with 105 clients, loosening its grip on the top slot for the first time since 2009. The last firm to pip the elite magic circle firm to the top spot by total listed clients was legacy Eversheds in February that year, when it had 110 stockmarket clients compared with Slaughters and legacy Norton Rose on 109 each.

Other firms to score well in the new ranking include Pinsent Masons in third place with 100 clients, followed by CMS with 99.

Pinsents corporate finance head Rosalie Chadwick commented: "Our ambition is to do more work with these clients and really kick on from that position [in the total stock market ranking]."

She said the firm's latest London capital markets hires of Gareth Jones and Julian Stanier, who joined the firm from Berwin Leighton Paisner last week, fit in with this plan.

Slaughters has retained its position at the top of both the FTSE 100 and FTSE 250 rankings, despite seeing its FTSE 250 client list drop by 1 to 34.

The top of the FTSE 100 table did not change on Q2, with Allen & Overy (A&O) in second place with 28 clients, Linklaters in third (25) and Freshfields Bruckhaus Deringer in fourth (23).

However, in the FTSE 250 ranking, A&O climbed into fourth place with 27 clients, knocking Freshfields into fifth, with 26 clients.

During the quarter, A&O gained one FTSE 100 client (BT Group) and one FTSE 250 client, UK fertilizer development company Sirius minerals.

Slaughters saw its FTSE 250 client list shrink by one following the takeover of UK engineering company Atkins by SNC-Lavalin.

Looking ahead, Ward said he expects a rise in listed company takeovers. "Obviously the story has been about sterling being devalued, making UK assets attractive financially – I don't think that's the only reason for more takeovers by foreign investors. A lot of transactions we'll see will be based more on fulfilling medium-term strategy."

Top 5 firms by total number of FTSE 100 and 250 clients: