Herbert Smith and Australian firm Freehills have opened the vote for their proposed tie-up, which will see the two firms enter into a full-equity merger if the deal goes ahead.

The vote, which kicked off at both firms on 18 June, will run until 28 June, with the outcome to be announced to each partnership on the final day.

Herbert Smith requires 75% of its partners to vote in favour of the merger for it to go ahead. If approved, the firms are planning for a 1 October integration date.

It is currently unclear whether the firms' partners will be remunerated on one common structure, or whether each outfit will retain its independent system while sharing from one profit pool.

Herbert Smith currently operates a rigid lockstep structure compared with Freehills' modified system.

The news comes after Herbert Smith held a global partners meeting to discuss the tie-up in London last weekend (16 June), with a large number of partners flying in from the firm's international offices.

The meeting saw details of the deal discussed, with partners encouraged to support the move. A merger was previously understood to be less popular with partners in the London headquarters than those in Asia.

Herbert Smith has been in discussions with Freehills since the last quarter of 2011, with the union initially planned to go live on 1 July this year, tying it in with the Australian firm's financial year end. This was later pushed back due to the complexities of working out the deal.

If confirmed, the deal will see Herbert Smith join a stream of leading UK practices making moves into the Australian market.

Linklaters sealed an exclusive alliance with Allens Arthur Robinson in April this year, while Ashurst and Blake Dawson combined their Asian operations and came together under the Ashurst banner on 1 March.