Shares in contractor and support services specialist Carillion have been overlooked, according to RBS who raises its target price slightly and keeps its 'buy' recommendation."We feel Carillion's shares have been somewhat overlooked, partly because of a lack of will in some quarters to understand the Eaga deal and partly because of the good run they have had so far this year," said the broker.The group announced in February that it would pay £306.5m for green support services business Eaga.While pre-tax profit beat expectations in 2010, RBS highlights the company's outlook which said that, despite the tough UK markets, the business should make further progress in 2011.The target price is upped to 457p, from 446p.---bc