Anglo Irish Bank chief executive Mr Seán FitzPatrick has spent €435,011 on 36,276 shares in the bank.
The purchase, which was recorded on Friday, was made as part of Anglo Irish's scrip dividend programme.
At yesterday's Anglo Irish closing price of €13.60, Mr FitzPatrick had already netted a paper profit of some €58,000 on his investment.
Mr FitzPatrick's total Anglo Irish holding of 1.19 per cent was worth €53.6 million last night. He was one of a number of the bank's directors to make scrip-related purchases last week.
The next largest transaction was registered by Mr Peter Killen, who bought 10,342 shares for €124,018. He has realised a paper profit of some €16,600.