Background: Tuas is an ASX-listed Singapore telco that was spun out of TPG Telecom in 2020 following TPG's merger with Vodafone in Australia. It's still run by TPG founder David Teoh and owns the Singapore budget mobile brand Simba. Last August, Tuas agreed to acquire Singapore telco M1 from asset manager Keppel in a $1.5 billion deal - a move the the ASX-listed company's shares up 30%.

What happened: Singapore's regulator raised concerns that Simba may have been using radio spectrum it wasn't actually licensed to use. So, the regulator suspended its review of the proposed merger, putting the deal into doubt just days before its May 21 completion deadline.

What else: The uncertainty is triggering major market reaction, with Tuas shares plunging 63% in a single day. It bounced back around 20% yesterday but it's still well below where it was before the regulatory setback around its radio spectrum use.

What's the key learning?

💡 Radio spectrum is basically invisible real estate, and every telco in the world is fighting for a slice of it. Spectrum carries wireless signals for services like phone calls, mobile data, and 5G, with governments assigning specific frequencies to operations.

💡 Spectrum licenses are highly valuable assets and a major source of revenue. In 2024, Australia generated nearly $722 million from spectrum auctions involving Telstra, TPG, and Optus. And the total value of spectrum licenses in Australia sits at around $8.2 billion.

💡 Using spectrum without a license can cause big problems. Operators pay heavily for access rights, so unauthorised usage can raise questions about whether a company should be allowed to operate... putting major deals, like Tuas' merger, under pressure.