IBI celebrated its 40th birthday thisweek as the market leader in the corporate finance sector, but with noroom for complacency, as Caroline Madden discovered

The great and the good of the Irish business world donned their tuxedos and ball gowns and descended on the Four Seasons this week,partly to hear guest speaker Charlie McCreevy but primarily to mark the 40th birthday of IBI Corporate Finance.

Over the last four decades, IBI has established itself firmly as the adviser of choice on mergers, acquisitions, disposals, flotations, MBOs, private equity fundraising and pretty much any other variety of corporate transaction you care to mention.

IBI has worked tirelessly behind the scenes on a great many landmark deals in the State's financial history - from the takeover of Irish Distillers in 1988, to the flotation of both Kerry Group and Jurys Hotel, from takeovers such as Smurfits and Arnotts, to the disposals of Tayto Crisps, MyHome.ie and BWG. All in all, it is a fairly impressive resumé considering IBI's Dublin office boasts fewer than two dozen professionals.

IBI started out on Stephen's Green in 1966 as a joint venture between Bank of Ireland, Morgan Grenfell and Schroders. In the intervening time it has consistently maintained its lead in the corporate finance market.

Mergermarket rated it the number one corporate adviser last year and Finance magazine has awarded it the 2006 Deal of the Year accolade for the Jurys Doyle Hotel Group take-private transaction.

Róisín Brennan is now leading IBI into its fifth decade, having recently taken over the reins as chief executive. "I've been in IBI for nearly half of its existence," she says. "I was very lucky because I had the opportunity to work for Richard Hooper [ chief executive for 25 years]."

Having come from a background of auditing in Arthur Anderson, she relished her first foray into the corporate finance world. "The first meeting I went to when I joined IBI was the privatisation of Irish Sugar." Working on such high-profile deals was "incredibly interesting", she says.

Since its genesis, IBI has been hugely active in advising public companies, but more recently it has diversified into the private companies market, and has built up quite a significant practice in this area.

Brennan explains that IBI spotted an opportunity in that a lot of indigenous Irish companies were looking either to exit the market or make an acquisition. "We just tailored what we do to assist companies like that.

"When we looked at advising the smaller companies as a specialty, what we wanted was to avoid the situation where people might have been deterred or maybe intimidated by the IBI name, and felt that we were too big for them."

She says that IBI works on transactions right across the spectrum from less than €10 million right up to the very largest deals.

"We absolutely do cater for the smaller people just as well as we do for the large."

She explains that while transactions on the private side are typically smaller than in the case of public companies, the volume is much larger.

Even though IBI has been a market leader since its inception, it cannot afford to be complacent, Brennan says, as the corporate finance environment is becoming increasingly competitive.

"When we started, it was very much the case that there were clients queuing up seeking to be advised by us, but the environment has changed in that it has become more competitive, and we have players both locally and internally in the market."

Companies see the value of having a local experienced adviser, she argues, and for that reason IBI continues to be very busy. "They see as well over the years the commitment that they get, and the benefit of having somebody on the ground."

Bloomberg's ringing praise confirms this view: "IBI is the top Irish takeover adviser . . . leapfrogging bigger international rivals . . . gaining a dominant position among Irish companies."

So what is the key to becoming - and remaining - a trusted adviser to the biggest names in Irish business?

According to Brennan, IBI operates on a number of key principles that others might consider old-fashioned: "Basic things like honesty, integrity, independence - those principles are very clear to anyone who joins IBI."

She also attributes its success to the people working in IBI: "Their commitment and willingness to go the extra mile for their clients is fantastic."

As far as possible, IBI strives to advance people internally, which seems to develop a sense of loyalty. "Over the years, we've often had what we call the 'boomerang effect' here, that people go and actually come back," she says.

As well as IBI's treasured clients and current staff,the guest list at the Four Seasons also included the "IBI alumni" - former employees, most of whom are still very active in Irish business.

So what does the future hold for IBI?

"The onus is on us to remain nimble," Brennan says, but other than that she's not ruling anything out.