Philip McGuigan has been selected to Replace Dathai McKay as an MLA at Stormont.
The Sinn Fein politician stood down last week over the NAMA Coaching Scandal.
It was alleged the former chair of the finance committee trained the Loylist Blogger Jamie Bryson on how to give evidence to a Stormont Enquiry.
It had been tasked to investigate a controversial £1.2 billion property deal which was later linked to an off shore Bank Account.
Mr.Bryson used the evidence session to suggest that a Northern Ireand politician received a £7million payment to secure the deal.
Mr.McGuigan's served as a councillor in the North Antrim area since 2001 and was an MLA from 2003 to 2007.
Sinn Fein Chief Whip Carál Ní Chuilín announced the co-option earlier.
"Following consultation with Sinn Féin activists in North Antrim, the Sinn Féin Ard Chomhairle has approved the selection of Philip McGuigan for co-option as the new MLA for the constituency.
"I have no doubt that with Philip's return to the Assembly will continue to provide first class representation to the people of North Antrim.
"I wish him well and look forward to working alongside him in the Assembly."
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