Nathalie Callie: Deals are more fun when you work together

In September 2026, Nathalie celebrated her fifth anniversary with PIA Group, one of the Benelux’s fastest-growing accountancy, audit and advisory firms – especially following its recent acquisition of ADC Group. When she started her career in finance in 1999, Nathalie might have already envisioned becoming a CEO one day, but she certainly hadn’t anticipated the shift her journey took along the way.

“I studied economics and started very classically, as an employee in an accounting department,” Nathalie rewinds. After almost four years at Ineos, she was appointed head of the finance department at Kranen Michielsens, while also earning her master’s degree in economics at the University of Antwerp (2003-2005). This was where Nathalie discovered her passion for M&A.

She arrived at Kranen Michielsens just as the family business was transitioning ownership from the father to his son. “The son was very ambitious; he wanted to make his father proud and turn the business into an industry leader within five years," Nathalie recalls. “So, he asked if I would be open to guiding him through buying some Belgian companies.”

As the head of bookkeeping aiming to become CFO, she wasn’t sure how she could support him without any M&A experience at the time. “I thought every business was structured more or less the same way and that M&A was buying a company, performing financial due diligence, then the deal is closed,” Nathalie says. “If all the numbers were fine, then everything else was, too.”

However, recognising that she needed help, the son hired an external specialist, Edwin Vervoort, to show Nathalie the ropes. The specialist would often remind her to think about the operations, the culture and everything else in between.

One of the learnings Nathalie still carries with her today is the importance of culture fit. “M&A really begins after the deal ends, when it’s time for integrating and you have to work together for the long term. If it’s not done correctly, you will lose people, who are the real value drivers in any business,” she conveys. “That’s why it’s crucial to take time to get to know the business you are acquiring. If you have a mutual understanding and respect, you can discuss anything and will always find a solution.”

Nathalie used this philosophy to help scale Kranen Michielsens into a leading position in Belgium’s industrial sector. Normally, the next step in scaling is to seek external equity, but the son decided he wanted to stay the sole owner, which meant Nathalie’s role reverted to the standard CFO responsibilities. So, in 2006, she left the company in search of a new challenge and joined USG as the financial director for Belgium in May 2007, because of its ambitious strategy (among other reasons).

“I had fallen in love with the growth part of the job.”

Shortly after joining, however, the banks went into crisis; M&A was frozen and the focus shifted towards restructuring the business. During this rethink, USG invested further in its shared service centre for its multiple brands. After this, she was asked to take on a VP Finance role in South West Europe, where she was (among other things) responsible for further development of the shared service centre across SW Europe.

She left USG People in 2016, “My job had been very international, so I decided to head back home to Belgium and dedicate more attention to my family while working,” Nathalie shares. She spent the next four years at Vandelanotte as the director of operations and staff. “They had a more classic vision on buy-and-build, but coming from a multi-brand background, it didn’t quite resonate with me, either.”

In September 2021, Nathalie joined PIA Group, which was then predominantly in Flanders, with only one smaller office in Brussels. “The company was very much still under construction after the impact of COVID-19 when I arrived, but what had stood out during our initial discussions was their confidence that there is room for the PIA model in our market,” she explains. “We believed in the same things. It was the same multi-brand strategy I had been part of at USG, and – having seen its success globally – I also believed in the PIA story.”

Being part of the team behind the PIA model was one of Nathalie’s biggest career milestones. Steven Brouckaert and Baltisse brought the vision, but together, they all constructed the structure. “We created central capabilities to support the local brands and enhance collaboration between them,” she says.

This cooperation was a non-negotiable for Nathalie. “I believed that, if we wanted to be a group, we had to act like one – that’s why culture fit is so important,” she emphasises.

As such, PIA Group is very selective about the businesses that join the portfolio. “We search for locally strong brands with standout people and a shared set of values,” Nathalie discloses, explaining that diversity is among its top requirements. “We believe it's a good sign of respect for your people and your clients. Because at the end, we are a people business.”

Read more about PIA Group’s buy-and-build strategy.

“Ultimately, we need to make each other stronger,” Nathalie echoes.

Considering cultures across the Benelux
Another benefit of the PIA model is that it scales well across borders, allowing the group to continue expanding its footprint. “When it’s important that a business stays local, especially for client relationships, it does,” Nathalie says. “We give them room to be in connection with their clients and centralise the services where it makes sense, such as technology, security and compliance.”

PIA’s recent acquisition of ADC Group is the perfect example of this model in action. “The group’s ambitions, entrepreneurial leaders and strong local presence – with offices spread across Eastern Belgium and Luxembourg – ticked all of our boxes,” Nathalie elaborates.

She believes that with a good game plan and team in place, ramping up PIA Group’s growth across the Benelux, Germany and beyond is possible: “With the ADC deal, for example, we had the experience of previous acquisitions – as well as the team’s own history working in the region – and the PIA model to fall back on.”

And when you don’t have the capabilities internally, you can always appoint external specialists to support your team, similar to Nathalie’s introduction to M&A or when she joined PIA Group. “PIA didn’t have a big M&A team at the time, so we would use specialists and external consultants wherever possible,” she divulges. Now, the company is doing its first deals in Germany and, once again, leveraging local teams with in-country experience. “It comes back to what I said earlier about respecting and taking time to discuss, listen and consider everyone’s opinion is the best way to find a solution. When you work together, especially when it’s not your mother tongue, you have to.”

Besides, misunderstandings can also arise from differing opinions or positions, not just from language. That’s why Nathalie suggests the real question should rather be whether both parties are truly willing to work together – i.e. in a group?

She echoes many community members, expressing that M&A is a very emotional business.

“M&A Advisors do a lot of deals, but for many companies/owners it’s a once-in-a-lifetime situation. When you reflect with them after the deal closes, you can feel the emotion that went into it.”

Nathalie heeds that this part is largely underestimated.

Things go further and faster together than they do solo
Consolidation across Europe is accelerating, and Nathalie expects this will continue for some time. “If you rewind a year, Belgium’s PE market mostly consisted of PIA Group – supported by Baltisse – and Moore – supported by Waterland –, but now we’re seeing the arrival of new PE’s,” she points out.

Moreover, she mentions that PIA is having conversations with offices that would not have been open to discussion back then. “With increasing AI and compliance pressures – not only in Belgium but also in Europe – business owners don’t want to make decisions on their own anymore.”

Nathalie is a proponent of the notion that you can go further and have more fun together than you do alone. This is where the PIA model comes in: “They see there is a group that respects their entrepreneurial power, culture and ambition,” she concludes.

During the M&A Private Equity Summit 2026, Group CEO, Ewout Brouwers, will unpack the thinking behind PIA's distinctive family equity model even further and why preserving entrepreneurial DNA can become a powerful source of alpha in buy-and-build investing. 

Register now for the Private Equity Summit, taking place on 22 October 2026 at Loyens & Loeff in Brussels, if you want to hear more.