PGA operates several golf courses, including a facility in Portugal which is leased from Mr O'Brien's Quinta do Lago operation.
Mr William O'Brien is by no means the first Irishman to marry his love of golf with a significant investment in the sport abroad.
The ultimate example in the genre, and one which puts the Hungarian move firmly in the shade, is the Sandy Lane development at St James in Barbados.
This exclusive holiday destination is owned by a consortium including well-known Irish businessmen - Mr Dermot Desmond, Mr John Magnier and Mr JP McManus.
The group paid €60 million to purchase the property during the 1990s, and then set about demolishing and refurbishing it at a reported cost of more than €100 million.
The re-development was complicated, but resulted in the opening of a fabulously opulent resort, including a spa, hotel complex and no fewer than three golf courses: the Green Monkey, the Old Nine and the Driving Range.
Green fees on the two larger courses vary between $85 (€86) and $140 per person.
Sandy Lane, which overlooks the Caribbean, has 112 luxury rooms and suites, all of which come equipped with extravagances such as wide-screen televisions, DVD players and heated bathroom mirrors.
Also putting Mr O'Brien into the shade is his namesake, former Esat chairman Mr Denis O'Brien.
Mr O'Brien bought a property at Quinta do Lago in Portugal at around the same period when he made his millions from BT's acquisition of Esat.
He handed over £25 million (€31.7 million) in the deal, which saw him take ownership of four 18-hole golf courses, a five-star hotel and a number of lakes suitable for sailing.
The opulent hotel counts 121 rooms and 20 suites among its accommodation offerings, including a Royal Suite with its own private pool.
All have air conditioning, balconies, satellite television, video players, internet data port system telephone lines and mini bars.
Late last year, Mr O'Brien built on this investment when he acquired control of European golf-course operator, PGA, paying €58.6 million for the 59 per cent of the company he did not already own.
