Bernie Ebbers, the founder of WorldCom, the telecommunications company, was portrayed alternately as a scheming chief executive and a kind-hearted, rags-to-riches entrepreneur as lawyers clashed yesterday at the opening of his criminal trial.

David Anders, assistant US attorney, said Mr Ebbers pressed subordinates to manipulate financial results and lied repeatedly to investors to hide the company's sagging performance. He sought to persuade jurors that Mr Ebbers undertook the largest accounting fraud in US history - totalling $11bn - in an effort to protect the company's share price and his personal wealth.