Macquarie Consortium Agrees to Buy SI Solutions Stake

Mark W. Marano has worked on both sides of the power industry's purchasing conversation, inside utilities and the companies supplying them. As President and CEO of SI Solutions, he now leads an engineering business preparing for another change in financial ownership, with its customers still depending on technical decisions about equipment already in service.

A Macquarie Asset Management-led consortium, including UniSuper, agreed on September 10, 2026 to acquire a majority stake in the Huntersville, North Carolina company from MidOcean Partners. Financial terms were not disclosed. The announcement anticipated a fall 2026 closing, subject to regulatory approvals and customary conditions; the reviewed primary sources do not establish a subsequent completion.

The proposed acquisition gives infrastructure investors a position in the expertise supporting existing plants and other critical assets. SI combines engineering, testing and software in a business built around understanding how equipment deteriorates and what an owner can responsibly do about it. The commercial opportunity follows the life of the asset, including the years after its original builder has moved on.

The majority agreement follows a specialist buying strategy

Macquarie Asset Management is the asset-management business within Macquarie Group. Its interest in SI fits a strategy of investing in companies that supply essential products, services and technology to infrastructure owners, with UniSuper participating as an institutional co-investor. This is a proposed change in majority ownership rather than a newly announced venture funding round, and the releases provide no basis for assigning a purchase price or valuation.

For the seller, the agreement follows a period of assembling a broader services platform. MidOcean's September announcement says SI completed 3 add-on acquisitions during its ownership and expanded its nuclear and advanced-reactor offering. MidOcean reported approximately 600 professionals across 16 US locations, including 5 testing laboratories, serving more than 330 clients at the time of the announcement.

Those are company-reported operating figures, not a measure of unused capacity available to a new owner. A specialist platform can expand its commercial reach while particular assignments still depend on the right people being available for a particular plant. For a buyer, the attraction lies partly in coordinating those capabilities across relationships the engineering teams have already earned.

Engineering judgment connects the platform's businesses

SI's ownership history helps explain the collection of capabilities. MidOcean's portfolio profile describes a platform formed by combining Structural Integrity Associates and C2C Technical Services, with SC Solutions subsequently added. The customer base spans electric and gas utilities, independent power producers, public agencies, process industries and the semiconductor value chain.

The businesses bring different kinds of technical work into the relationship. SI's company overview describes Structural Integrity Associates' infrastructure analysis and lifecycle management, C2C's engineering and electrical construction, SC Solutions' model-based controls, and Integrity Specialists' inspection capabilities. A client may encounter the group through a specific assignment while needing expertise elsewhere in that collection as a project develops.

In February 2026, SI's Structural Integrity Associates division acquired Radiological Solutions, adding nuclear plant chemistry, radiation protection and related operating support. That expansion shows how the platform has been widening the work it can undertake around a facility. The commercial question is how well the organization connects those disciplines for the customer, including when a problem crosses the boundaries of an original contract.

Software stays close to the physical equipment

The software component of SI's offering is easiest to understand through the decisions it supports. In its description of SIIQ monitoring for a combined-cycle facility, SI explains how operating data and damage models can help identify deterioration before it progresses to failure. PlantTrack can retrieve information from a plant historian, while SI experts review relevant data to help determine an appropriate response.

That arrangement puts software inside a continuing engineering relationship. Monitoring may identify a problem worth addressing or supply evidence that supports an inspection decision, according to SI's technical account. The value depends on connecting measurements to the actual component and its operating conditions, making domain knowledge part of how the data becomes useful to the plant.

SI's MAPPro account describes another part of that relationship: managing aging piping through risk analysis, inspection planning and layered location data. These are company descriptions of technical capabilities, rather than independently audited performance results. Together, they show why separating the software story from the engineering business would leave out much of what the customer is buying.

Continued service creates a continuing customer relationship

The physical constraints become especially clear in SI's Turkey Point tank-inspection case study. The company describes using remote inspection platforms for a radiological water tank at Florida Power & Light's nuclear site, with equipment access limited by a 24-inch opening. The job required an inspection approach suited to the contamination, geometry and available operating window.

That is a concrete example of the expertise sitting behind an infrastructure-services investment. Customers need work that can be carried out within the conditions their assets impose, and findings that support a defensible operating decision. Bringing more disciplines under common ownership can help coordinate that work, although the acquisition announcement does not promise specific customer savings, pricing changes or service outcomes.

Marano's official biography spans utility roles and senior positions at power-industry suppliers, including Westinghouse. That experience is relevant to a business whose recommendations have to survive contact with a customer's operating responsibilities. As the proposed ownership change advances, SI's expansion will keep meeting that responsibility in individual assignments: which specialists arrive, how their findings fit together, and what the plant's team can do with the answer.