In 1997, Sean Corkery got a call from a headhunter acting on behalf of Denis O'Brien. "I didn't know Denis from Adam," he says.

Corkery was in charge of global operations for AST Computers. O'Brien, then an up and coming telecoms entrepreneur, was about to float Esat Telecom on the Nasdaq in New York.

One Friday afternoon he met Leslie Buckley and Mark Roden, two Esat executives. "They liked me. I went off on the plane on the Saturday or Sunday to Boston to meet Denis, where he was doing a roadshow for the flotation."

O’Brien liked him too. He was hired as Esat’s chief operations officer, and held the position until it was sold in 2000. Corkery then joined Dell, although he maintained his links with O’Brien’s camp.

Earlier this year, O'Brien called for him again. More than a year previously, the telecoms billionaire had snapped up Siteserv – a meal deal of construction services businesses cobbled together during the boom – for a knockdown €45 million.

When O'Brien bought it in April 2012, Siteserv was out for the count – insolvent, ineffectual, in a heap, and in need of rescue. O'Brien negotiated a controversial debt write-off of €90 million from Irish Bank Resolution Corporation, more of which later.

Corkery took over as chief executive and chairman of Siteserv in July of this year. His brief? Nothing less than transformation.

“I am a change-oriented guy: transformation is what I do,” says the immaculately-coiffed Corkman, stirring his coffee in the upstairs lobby of the Westbury hotel.

Corkery – calm, adroit, reserved, calculating – will need all of his skills to fulfil the task. As anyone in O’Brien’s circle will tell you, the billionaire hates being disappointed.

Siteserv was expensively assembled in the noughties by its founders, Brian Harvey and Niall McFadden. They bought a succession of different companies at boomtime prices. All were in some way or other related to the construction industry.

Harvey did “a reasonable job of bringing five or six businesses together” before he quit as chief executive earlier this year, Corkery says. “But you could argue he paid way too much for all of them.” Then again, didn’t everybody pay too much for everything back then?

Siteserv, the holding company, consists of six main operating units. Sierra, which under the old regime was mainly a civil engineering business, is the largest at 40 per cent of the company.

The other Siteserv pillar is Deborah Services Limited (DSL), an industrial services provider, which Corkery wants to grow quickly in the UK and Ireland.

Together, the two units account for more than three quarters of Siteserv’s revenues, which Corkery says will hit €230 million this year, up about 25 per cent. Profits, Corkery says, are “about seven per cent”, or up to €16 million this year.

The other fifth of its revenues comes from a combination of Eventserv, which supplies fencing and stages to concerts; Holgate, which specialises in motorway noise barriers; Roankabin, which supplies prefabricated buildings; and Siteserv Access and Formwork, which supplies scaffolding.

The group employs about 3,000 staff – 1,300 in Ireland and 1,700 in the UK. It has picked up a host of new contracts since O’Brien bought the business. The billionaire has invested a further €50 million in it since he got the keys.

Corkery is currently devising a new three-year growth strategy for Siteserv, part of which involves positioning it as the infrastructural “sister company” to Digicel, O’Brien’s Caribbean mobile operator. Corkery joined Digicel’s board last month.

Construction expertise
His aim is to continue to diversify the group away from construction. Instead, it will chase recurring revenues providing services to other businesses. "If the building boom comes back, we're not interested," he says.

Since the building boom collapsed, its linchpin Sierra has moved from civil engineering "into the home" as an installer and maintenance contractor for utilities such as Sky, UPC and Bord Gáis.

It also recently picked up a huge contract installing Irish Water meters as part of a joint venture with GMC, and it also has a big contract in the UK with Scottish Power.

“The old yellow Sierra engineering trucks, the guys digging up the road – that’s almost gone. It used to be 30 per cent of the group, now it’s less than 10 per cent,” Corkery says.

The company has retained a small amount of construction expertise.

“We still have a few yellow vans out back. They don’t turn me on, but they’re there. We need to keep some civil engineering capability, but mainly for consulting. For the work, we bring in contractors.”

Corkery comes from solid working- class stock. His father was a bus driver in Cork city, and the family placed a heavy emphasis on education. Corkery's school didn't offer economics as an option, so he did it himself for the Leaving Certificate and went on to study the dismal science at University College Cork.

After a brief stint as a secondary school teacher – “I didn’t have the patience” – he joined Apple’s graduate programme in 1981. He spent 13 years at the company, working his way around the world to senior management level before joining AST and then Esat.

After O’Brien sold the telecoms company, Corkery joined Dell. Once again, he spent 13 years with the company in senior globalised roles, culminating in a stint as its head of global supply chain operations.

Corkery was the man who closed Dell’s plant in Limerick in 2009, with the loss of 1,900 jobs. Limerick, which was devastated by the closure, is also where Corkery has lived since his AST days. He defends the decision as one that was “absolutely necessary”. He isn’t a robot, however.

“I think I dealt with it really well, at the time. But it did become difficult. I kept coming home at weekends to a city where almost everyone I met had been affected in some way. That wasn’t great. But imagine where the company would be now if we hadn’t done it?”

Towards the end of Corkery’s time at Dell, O’Brien bought Siteserv. The deal was controversial because there were reportedly higher bids on the table that were rejected, which arguably could have yielded a better payout for the State-controlled IBRC. Siteserv said the other bids were too conditional.

The deal was also criticised because shareholders, including Harvey, walked off with €5 million of the cash. With insolvent companies, equity is normally wiped.

Is Corkery satisfied that any lingering questions surrounding the deal have been sufficiently answered? He is well prepared for the line of questioning, batting it away like Babe Ruth.

“That issue is never raised by our customers or employees. Anyway, I can’t comment because I wasn’t there. You’re the first person to ask me about it,” he says.

He stops to think for a second.

“Look, from what I read, there was a tender process and the best man, the best bid, won the process. The employees were delighted when they found out who won it. It brought implications of growth, of a war chest, of synergies.”

One of the obvious synergies is with Digicel. Corkery wants Siteserv to work closely with O’Brien’s telecoms company, as its infrastructure partner.

"We should follow the Digicel map. It is in high growth, weak infrastructure markets. We're doing that already, in Papau New Guinea, Jamaica. If we didn't have the shareholder we have, it would be harder to go there. You'd spend years knocking on doors and people still wouldn't know who you were."

Back in Ireland, it is talking to ESB about helping it string a high-speed fibre network across electricity poles around the country. It is also trying to win business from the utility installing digital meters.

The company wants to follow some of its larger international clients, such as the power plant operator Ineos, into other markets. Ineos has asked it to tender for a plant in France. Siteserv also wants to work more with Sky.

“If you become an international supplier to these big companies you can grow very fast,” he says.

Away from the boardroom, Corkery says he is a straight up, simple guy.

“I’m family and company oriented. I’m not a guy that sky dives or does yacht racing. I have my two grandkids in Limerick, and I’m really just a young granddad. I mean, I do wheelbarrows with them and everything.

“But in business, I like to transform things. Denis likes the businesses he buys. I am going to transform this one into something he will like even more.”

Music to O'Brien's ears.

CV Sean Corkery

Name: Sean Corkery
Position: Chief executive and chairman of Siteserv
Age: 55
Home: Limerick
Family: Married, with three daughters
Something you might expect: "I like change."
Something that might surprise: "I'm very proficient at sign language, as I have a profoundly deaf daughter. I was a founder member of a parents for the deaf group in Limerick. We built our own school. I'm proud of that."