The merger of accountancy firms BDO and PKF has been approved by both companies and is set to be complete by spring 2013.

Talks were in the advanced stages last month for the creation of a firm, under the BDO brand, that will comprise some 3,500 employees in the UK and generate revenue estimated at nearly £400m.

BDO International has revenues of over £3.7bn operating in 138 countries worldwide. 

“This is transformational, for our two firms but also the broader market,” said Simon Michaels, managing partner of BDO.

“The merged business will have firm financial foundations and an ambition to grow. Both firms employ many talented people capable of delivering quality work to a range of clients, across audit, tax and advisory.”

Martin Goodchild, managing partner at PKF (UK), added: “The strategic decision to merge has now been made by the partners of both firms.

“Our primary focus as we move to completion will be to ensure both our clients and people benefit from the merger; they will be working with a resilient partnership leading from a position of strength and with a client service ethic at its heart.”