Disposal

Costain Group PLC

("Costain" or "the Group" or "the Company")

Disposal of interests in Zimbabwe contracting subsidiary

Costain, the international engineering and construction group, announces the sale of its interests in the Zimbabwe contracting business, Ceezed Construction (Private) Limited ('Ceezed'), which was formerly known as Costain Zimbabwe (Private) Limited. Costain's interests have been sold to a consortium headed by Ceezed Executive Chairman, Mr T.P. Chimuriwo, for £0.5 million in cash.

Costain confirms that it will have no future involvement in Ceezed.

11 April 2011

Notes to editors:

Costain (www.costain.com)

Costain is an international engineering, construction and maintenance group with a reputation for technical excellence founded on more than 140 years of experience. The Company's business segments are in Infrastructure (Highways, Rail, Nuclear and Airports), Environment (Water, Waste, Marine and Education), Energy & Process (hydrocarbons & chemicals, nuclear process and power activities) and Land Development.

The Company is focused on market sectors where it expects there to be a significant investment driven by national needs.

It has worked on a number of significant infrastructure projects in the UK, including the St Pancras railway station and the Channel Tunnel Rail Link, and is currently working on a number of significant projects including the municipal waste treatment infrastructure for the Greater Manchester Waste Disposal Authority and EVAP D at Sellafield, one of the largest nuclear projects in the UK.