Business at executive-recruitment companies is improving, buoyed by increasing confidence among corporate leaders and a stabilization in hiring for senior positions in the financial-services industry, Bloomberg reported. Heidrick & Struggles International Inc. and Russell Reynolds Associates say they see some increase in demand, a trend that was echoed in a recent survey of consultants by William Blair & Co., an independent investment firm. Meanwhile, economic confidence among chief executive officers strengthened in April to the highest level in almost two years, as the Chief Executive magazine confidence index rose to 6.07 from 5.55 the prior month, based on an e-mail survey conducted by the magazine.