"Among the mid-caps, Expro International led the risers after a private equity consortium led by Candover said it reached an agreement to buy the British oil and gas services company for £1.6bn. Its share price jumped 123p, or 9% to close at £14.45p, a sign that investors expect a rival bid."
http://www.guardian.co.uk/business/2008/apr/18/construction.marketforces