PITTSBURGH (AP) – Pittsburgh’s biggest law firm is merging with the Australian firm, Middletons, and will add 300 attorneys in four offices as part of the deal.

The law firms say in a joint news release that the merger takes effect Jan. 1 and that the combined firm will operate under the K&L Gates name.

With the merger, K&L Gates will have more than 2,000 attorneys in 45 offices on five continents.

Middletons currently has 300 attorneys in the Australian cities of Sydney, Melbourne, Perth and Brisbane.

The firms say their respective partners voted unanimously to merge.