Russia's Egorov Puginsky Afanasiev & Partners and leading CIS firm Magisters are set to merge, creating the biggest firm in the region.

The merger, which was announced today, will create a law firm with combined revenues of around £101m and more than 300 lawyers – including 27 partners – with a launch date yet to be announced.

The merged entity will have five offices across Russia and the CIS, as well as a further two associate offices in London and Washington DC, and will operate under the name Egorov Puginsky Afanasiev & Partners.

Egorov chairman Dimitry Afanasiev said: "This merger is unprecedented for our market. We are a step ahead of any national or international law firm in size, market penetration and regional coverage in Russia and the CIS. Growth through consolidation is necessary to sustain the positive momentum in our development as the leading firm in Russia. Together we can do more.

"Both firms share the philosophy of international excellence combined with unique local knowledge and this makes us a perfect fit for each other. We are determined to bring new value to our clients through this merger. We are also excited to be the trailblazers in the CIS."

Egorov, which has established referral links with Slaughter and May, specialises in litigation and corporate work, while Magisters offers services across the board including practices in oil and gas, tax and white collar crime.

Both firms have advised on a number of high-profile international deals in recent years with Egorov taking a role for on the €1.5bn (£1.3bn) merger of Russian dairy company Unimilk with the local arm of French foods company Danone last summer.

Meanwhile, Magisters acted on the largest merger in Ukranian history in May 2010, when Russia's Altimo and Norway's Telenor combined their stakes in cellular operators Russian Vimpelcom and Ukrainian Kyivstar GSM to create Vimpelcom in a $23.8bn (£14.7bn) deal.