The shares were sold at €1.84 each, bringing the total sale to €14.72m.
Mr Stanley, who has led Cairn for the past decade, held over 21.7 million shares in the business at the end of last year.
This represented around 3.36pc of the ordinary share capital of the business in March this year, according to the company’s annual report.
The news of the sale comes following the publication of the company’s half-year results earlier this week.
Revenues were €366.1m in the period, up 67pc from the same time last year. Operating profit also soared 107pc to €61.4m.
Operating margin jumped to 16.8pc in the first six months of 2024, up 330 basis points compared to the corresponding period in 2023.
Cairn’s closed and forward order book has risen to 3,450 new homes with a net sales value of €1.32bn.
“The company has delivered a stellar half-year performance across all key metrics, most importantly in housing delivery with our turnover increasing by 67pc year-on-year,” Mr Stanley said.
“By the end of this year Cairn will have delivered over 9,500 energy efficient new homes to our customers across Ireland,” he added.
Mr Stanley also reported earlier this week that the total number of housing completions will be close to 40,000 this year.
Despite relatively weak numbers in the first half of the year, Mr Stanley said a late surge in completions – including by his own firm – will lift the finally number well ahead of the 2023 level.
The head of the stock-market-listed developer said the sector has the potential to go up again in 2025 – by as much as an extra 20,000 units.
That would bring construction above the Government’s increased targets for around 50,000 new homes.
“The industry has the capacity to build another 20,000 units, including the labour – but the capital required is considerable,” he said.
Government financial supports for home buyers and to providers of social and affordable homes are a major factor in the market – but private capital is also required on a significant scale to hit the targets now being talked about, he said.
Labour shortages, long flagged as a potential bottleneck to ramping up supply, are not proving a hurdle – because skilled people are diverting from commercial schemes to residential as demand shifts, he also reported.