Marconi, the UK's embattled communications equipment group, has issued its fifth profit warning in a year. The company has embarked on a series of disposals of non-core assets over the last year. The few remaining assets to be sold include: a 72% stake in Easynet, Payphones and Mtech (electrical components). It recently announced plans to sell its secure communications business, based in Italy, which could be worth about £300m.