The full financial integration of Ashurst and its Australian arm has been approved by both partnerships and will take effect on 1 November 2013.

The vote – which opened on 10 September for Ashurst partners – closed this morning and required a 75% majority for the combination to go ahead.

The merged firm will have a single profit pool allocated on a managed lock-step system and a single unified management structure operating globally as one firm under the Ashurst brand.

The vote follows the announcement in 2011 that the firms would combine their businesses in Asia and re-brand Blake Dawson as Ashurst in March 2012. Initially the firms had committed to merge by 2014 but the merger vote was brought forward by six months.

Charlie Geffen, Ashurst senior partner, said: "We have received overwhelming support from both partnerships and are absolutely thrilled at this result. We are the only firm that has created a fully integrated single profit pool remuneration structure. By taking our time it has given people the opportunity to get to know each other and this has been the best outcome."

Australia managing partner John Carrington added: "Our Australian clients will continue to benefit from a committed full-service law firm in Australia, with the added benefit of international reach and expertise, and a growing platform in Asia Pacific."

The combined firm will comprise of more than 3,500 people, including 1,800 lawyers across 28 offices in 16 countries, with a combined revenue of more than £550m (A$930m).

Earlier this week it emerged that Ashurst dispute resolution partner Ben Tidswell and legacy Blakes competition and consumer protection partner Peter Armitage will run against Geffen for the role of chairman of the merged firms. Voting will take place between 27 September and 15 October with an announcement expected the following day. Voting on the vice-chair role will follow shortly afterwards.

Partners will also vote on a new board which will comprise 14 members including the chairman, vice chairman, global managing partner James Collis and CFO Brian Dunlop.