The proposed job losses will be spread across the UK, including 100 in the West Midlands, almost 100 in Shotton, North Wales, 50 in south Wales and 50 in Leeds.
The company attributed the action to the economic downturn and a volatile and fluctuating market.
The smallest of the blast furnaces at Scunthorpe, known as "Queen Bess", will close temporarily, starting this month.
Corus said: "The impact and continuation of the global economic downturn is having a major effect on steel customers in the automotive, construction and plant and machinery markets. Since September, the business has seen a significant decline in demand.
"As a result, Corus Distribution has introduced a series of actions to reduce expenditure on transport, consumables, energy and other discretionary spending. However, these actions alone will not be sufficient to offset the decline in the market."
Corus announced in October it would be cutting production by 20%
Corus said it will start an immediate consultation with workers and will try to achieve the job losses through voluntary redundancy.
The distribution side of the business employs 2,400 workers at 36 sites in the UK and Ireland. The proposed reductions will be spread throughout the business.
National officer at the steelworkers' union Community Roy Rickhuss said: "We welcomed the original Corus approach to the current downturn - to avoid knee-jerk reactions and not just cut jobs - so we are disappointed this has not been followed in Corus Distribution. ."