Dunnes Stores has executed a streamlining of its Byzantine corporate structure by centralising the previously disparate ownership of many of its Irish stores through a single company. The simplification of its structure could potentially make it easier for Dunnes to separate its business along geographic lines in future, if the family behind Ireland's largest indigenous retailer was ever to sell part of the business.

Dunnes last month merged at least 16 parts of its corporate structure into one entity, Dunnes Stores Ireland Company (DSIC), which has long been an important cog in the group but never before owned all 115 stores in the State.

DSIC has taken over ownership of stores including those in Arklow, Cavan, Letterkenny, Tralee and Kilnamanagh in west Dublin. The 16 merged businesses, which also include several property and holding companies, were previously owned by a variety of other companies in the group.

In turn, DSIC, which was previously controlled by two Isle of Man entities, has issued shares to other Irish companies in the Dunnes Stores empire, whose constituent companies are mostly registered with unlimited status, giving a veil of secrecy over the group’s finances.

Ownership of its business ultimately flows, via an Isle of Man company Benlettery, to the Irish-registered Dunnes Stores Holding Company. It, in turn, is owned by a trust company operated by the Dublin law firm, William Fry.

The association with Fry's company, Lower Mount, shields the exact details of the ownership split of Dunnes Stores among the family comes via three classes of ordinary shares in the holding company. However, accounts recently filed for the handful of unlimited entities in the group show that one-third of the shares – an entire class – are owned by Frank Dunne and his family.

Most of another equal-sized class of shares are owned by chief executive and family matriarch, Margaret Heffernan, and her family.

The ultimate ownership of the final third of the business is unclear from the company documents, but some of it may be in the hands of the next generation of Dunnes who will likely take over the business from Frank and Margaret. Dunnes did not respond to a request for comment on the streamlining of its business here.

Documents recently filed with the Companies Registration Office also show that EY resigned as auditor to the Dunnes group in the run-up to Christmas. EY filed a standard letter saying there were no issues of which lenders or shareholders needed to be made aware, so it is likely a standard change of auditors, which large organisations do every few years. EY took over in 2011.

Dunnes, Tesco and SuperValu are currently vying to be the largest grocer in Ireland by market share, with no sign of an abatement in 2016 in the cut-throat competition that has dominated the sector in recent years.