According to BBC, staff were told on Wednesday that 845 jobs would go at the site.
BAE originally planned to cut 899 of the 1,300 posts in Brough, but last month it said 54 technical and engineering jobs would be saved.
According to BBC, a BAE spokesman said that staff had been applying for voluntary redundancy and were being offered opportunities at the firm's other sites, both in the UK and Australia.
Read more: UK – A modest recovery in steel industry
"BAE Systems has informed employees that it has now concluded consultation on the business proposal to potentially end manufacturing at Brough," he said.
"This is due to no viable and practical alternative being found despite the extensive and meaningful consultation that has taken place with the trade unions and executive representatives.
Read more: Solid performance by BAE Systems in fiscal year 2013
"The company, during the next stage of consultation, will continue to focus on reducing the number of redundancies and, as far as possible, explore all opportunities to mitigate the potential job losses."
BAE said manufacturing would end at the site in the middle of 2013