Canadian Auto Workers President Ken Lewenza will announce Thursday that he’s stepping down in September, when a merger with the Communications, Energy and Paperworkers Union of Canada takes effect, a union source has confirmed to CTV News.

The CAW and the CEP are holding a news conference at noon ET on Thursday. Their news release only said that the unions “will be making an important announcement regarding the future union leadership of Unifor,” referring to the union’s new name.

When the merger was announced, it was unclear whether Lewenza or CEP president Dave Coles were planning to seek Unifor’s leadership.

Lewenza was elected national president of the CAW in 2008.