Only Four Companies in the World Can Build Submarine Cables

A submarine cable is no ordinary wire. It is a precision system that withstands deep-sea pressure, stays in service for decades, and even delivers electrical power to repeaters along the way. Only a handful of companies can build one, and only a handful of ships can lay one. For the full picture, see our complete guide to submarine cables.

Who Builds Submarine Cables?

Four companies account for the bulk of submarine cable manufacturing and installation.

The most telling development involves the market leader, ASN. In 2024, ASN was separated from Finland's Nokia, and the French government acquired its shares, nationalizing the company (at an enterprise value of around 350 million euros). It is a symbolic moment: submarine cables are now treated as critical infrastructure that states hold directly. This is a security theme continuous with the broader geopolitics of semiconductors (Carnegie Endowment).

NEC and the Role of Japan's Cable Ships

Here is a distinction that is easy to miss: the company that builds the cable and the company that lays it are not the same. NEC is a manufacturer — it makes the cables and the power-feeding equipment. Actually going to sea to lay cable, or to haul up and repair a broken one, is the work of cable ships.

In Japan, that role falls to the KDDI Cable Infinity, operated by KDDI Cable Ship. This 133m multipurpose vessel lays not only telecom cables but also power cables and ocean-observation equipment, and can even serve as an offshore base station in disasters. Just as Japan is indispensable in chipmaking equipment (the chip industry cannot run without Japanese equipment), Japan maintains a real presence in submarine cables on both the manufacturing and installation sides (KDDI Cable Ship / KDDI news release).

Who Owns the Cables?

Submarine cables used to be built and owned by consortia — groups of telecom carriers pooling the cost. That structure has changed. Hyperscalers such as Google, Meta, Microsoft, and Amazon now build and own cables of their own.

The share of international submarine capacity used by the four biggest players leapt from about 10% in the early 2010s to over 71% in 2024. For companies moving massive volumes of data for video, cloud, and AI, securing their own capacity rather than renting someone else's translates directly into competitiveness (Verdict / TeleGeography).

How Big Is the Market, and How Fast Is It Growing?

Market-size estimates for submarine cables vary because research firms define the market differently. The leading forecasts line up as follows.

The numbers span a range, but every forecast points up. New construction is booming too: in the three years 2023-2025 alone, roughly $10 billion was spent on 78 new systems totaling about 300,000km. Behind it all is the surge in international traffic driven by cloud and AI. Demand for links between AI data centers is expected to push cable investment even higher (MarketsandMarkets).

Key Takeaways

• Effectively four major manufacturers can build submarine cables: ASN, SubCom, NEC, and HMN.
• ASN is the world leader; in 2024 it was carved out of Nokia and nationalized by the French government.
• NEC is the manufacturer, while laying and repairing cables is done by cable ships such as KDDI Cable Infinity — a clear division of roles.
• Ownership has shifted from carrier consortia to hyperscalers: Google is involved in 33 cables, Meta in 21.
• The market is projected to reach $33-44 billion by 2030, with AI and cloud accelerating investment.

This article is not investment advice.