The Information Commissioner rejected claims this would damage the commercial interests of Celtic Wealth Management.
In 2014, Tata restructured its £14bn pension pot – with the UK government saying it failed to protect 124,000 members from a “mis-selling scandal”.
Pontarddulais-based Celtic Wealth Management was one of those implicated.
The Welsh Government initially refused to release details of the grant it gave the firm following a Freedom of Information (FoI) Act request by a BBC Wales journalist.
However, the Information Commissioner has now ordered it to do so by November.
Indian-owned Tata now owns the former British Steel operations – employing more than 8,000 people across England and Wales, with 4,000 in Port Talbot.
But those numbers are dwarfed by the 100,000 retired workers who are enrolled on its pension scheme – with Tata saying it would become insolvent if it continued sponsoring it.
A restructuring took place in 2017, with the Work and Pensions Select Committee later saying Tata failed to protect workers from “vulture” financial advisors, calling them “parasites” in a report.
One scheme member said he lost £200,000 after being advised to transfer out of it, with many others losing significant sums.
Celtic Wealth Management was one of those accused of cold-calling members of the scheme.
A BBC Wales journalist asked the Welsh Government for details of £118,500 given to the company in 2014 through an FoI request.
The request asked for evidence of how Celtic Wealth Management met the terms of the grant as well as an independent auditor’s report and any other details of the grant agreement.
In refusing, the Welsh Government said releasing this information would put “commercially sensitive information” in the public domain, benefitting the firm’s competitors.
This argument was supported by Celtic Wealth Management who said it would be “very unlikely” that it would “survive as a business” if those details were released.
When it refused, the journalist appealed to the Information Commissioner, who called the Welsh Government’s arguments for refusing “contradictory”.
The commissioner concluded the Welsh Government failed to show “a clear causal link” between releasing the details and potential damage to the company’s commercial interests.
A submission by Celtic Wealth Management was also called “poor and unfocused”.
“It was arguing both that the withheld information contained nothing which would shed light on CWM’s business methods and that disclosure would be so damaging to CWM’s reputation that it would be likely to threaten the company’s very survival,” the decision stated.
The ruling argued there was nothing in the withheld information to suggest any of those involved had acted improperly.
Details, with any personal information redacted, must now be released by mid-November.