The rationale behind Carroll's acquisition of Dermot Desmond's 21.6% of Greencore seems transparent enough, however. Estimates of the value of Greencore's land bank of four sugar-processing sites have been as high as 200m, making them attractive targets for a developer.

There is a widespread belief that Carroll will keep buying Greencore shares this week, and the 29.9% threshold is unlikely to be his ultimate target. At that shareholding level, Carroll would be an interested party, curtailing his potential input into decisions on the future of the sites. Speculation is mounting that he is prepared to go further.

Carroll certainly has the fire power to have a tilt at Greencore, and his record suggests he will be willing to go for the whole company if he thinks the opportunity attractive enough, and to deal with the non-property assets afterward. Sources close to the developer suggested that he was prepared, if the cards fell favourably, to buy Jurys Doyle lock stock and barrel last year.

Carroll set the cat among the pigeons in the protracted Jurys Doyle battle when he bought into the company as the takeover battle gathered momentum. So excited was outgoing Bord na gCon chairman Paschal Taggart by the developer's entry into the hotel fray that he bought into Jurys Doyle on the conviction that Carroll would take it over and that there would be tasty windfalls all round.

Taggart was hoping for a repeat of Carroll's highestprofile intervention in the world of Irish plcs, back in 2002, when Carroll took over property company Dunloe Ewart. Taggart played a pivotal role that time round in breaking the deadlock in the takeover battle between Carroll and Noel Smyth. History wasn't to be repeated with Jurys Doyle, but the developer still profited on a quick share flip.

It is hard to put a value on Carroll . . . close to 300m has been hazarded . . . beyond the certainty that he is loaded.

The last accounts filed for Carroll's Danninger show that it made a 50% increase in pretax profits in 2001 to 24m, had sales of 97.1m during the year and had development land of over 50m on its balance sheet. In 2003, Carroll turned Danninger into an unlimited company. Holding company Vantive Holdings is also unlimited, as is Dunloe Ewart.

Carroll made his early money by energetic and ubiquitous building. He achieved certain notoriety in his early days as a developer, when his Zoe Developments was the most active apartment block builder in Dublin. The Zoe apartments were often criticised as shoeboxes and the company also had a poor safety record. In 1997, Carroll was labelled a "recidivist criminal" by High Court judge Peter Kelly in a safety case.

After once commenting that architects were "only interested in designing penthouses for fellows with Mercs", Carroll first hired an architect for the Millennium Tower on Dublin's Charlotte Quay. Other major recent developments have included Dublin's Gasworks site, the Cherrywood scheme off the N11 and redeveloping Loreto Abbey in Rathfarnham.

He was in negotiations with the Dublin Docklands Development Authority over the construction of the planned U2 Tower, beside which he owns a site, but these negotiations have concluded. The DDDA is now set to put the development out to tender.