The High Court claimed he had breached the terms of his employment by poaching another employee over lunch.
Investment manager Fahim Imam-Sadeque, 41, had been head of sales for the UK, Middle East and Australia at Royal Bank of Canada's Bluebay Asset Management Services, one of Europe's largest managers of fixed income credit and alternative products.
He was paid nearly £2.5 million per year and managed assets of more than £24 billion.
But after announcing that he was to join a new asset management company, Goldbridge Capital Partners, as head of sales and marketing from January of this year, Imam-Sadeque was put on gardening leave by Bluebay in August last year.
Before leaving, however, he invited a colleague, Damian Nixon, out to lunch, following an email exchange.
Although Imam-Sadeque denied trying to poach him, the judge, Mr Justice Popplewell, rejected his claim.
Popplewell said the two men were friends as well as colleagues and he had recruited Nixon for BlueBay and "was the obvious candidate for making the first approach to him, to sound him out, and to talk to him in a way best suited to secure his ultimate recruitment which was the desired objective."
He ruled that the purpose of the lunch was to encourage him to join Goldberg, which he did, and work out a timetable for doing so.
He found Imam-Sadeque to have been in 'serious breach' of his terms of employment and said if BlueBay knew then what it knows now he could have been dismissed for gross misconduct.
He said he was not entitled to the bonus and his claim must fail.
A spokesman for London based Bluebay, which also has offices in the US, Japan, Hong Kong and Luxembourg said: "We are pleased with the Judgment of the High Court in this matter. BlueBay does not enjoy litigation.
"The firm does, however, require its partners, employees and ex-employees to honour their obligations to the firm, to tell the truth and to meet certain standards of ethical behaviour."
The spokesman added: "We note that the Judge found not only that Mr Imam-Sadeque's conduct was in serious breach of his obligations to the firm; but also that the sworn evidence he gave in Court was variously unconvincing, not plausible, not credible, untrue and false.
"We regard both the Judgment itself, and the specific findings in the Judgment in relation to elements of Imam-Sadeque's evidence, as fully vindicating our decision robustly to defend the firm's interests in this matter."