Chief executive Stuart Doughty said the bonus schemes would provide an incentive to executives at a time when the company aimed to increase turnover 15% a year for the next three years and improve margins to 3%.
Doughty said: "You have to get everyone to buy into what we are trying to achieve and align staff interests with the shareholders'."
The first scheme, which will last for a year, is open to about 50 senior staff and could earn them bonuses of up to 50% of their salaries for what Doughty described as "exceptional performance". The second scheme is open to a top layer of 12 managers and lasts three years. The managers will be allocated share options depending on the growth targets they meet.
Costain last week posted a pre-tax profit of £8.7m, an increase of £2.2m for the year to 31 December 2001. Turnover rose 20% from £386.3m in 2000 to £462.9m. Margins increased slightly but are still under 2%.
Doughty said the closure of Costain's Scottish office had cost £700,000 and had led to 10 redundancies. He added that the group's new Birmingham office was pitching for work.
Doughty said Costain was no longer interested in one-off design-and-build contracts as the risks were unacceptable. He said the group wanted to grow its long-term relationships with clients.
Costain has appointed Charles McCole group finance director. He was formerly with multiservice provider Sodexho UK.