Britain’s Vodafone and France’s Altice formed a joint venture on Monday to challenge Deutsche Telekom and build Germany’s €7 billion ($6.8 billion) fibre-optic broadband network.

Vodafone said the FibreCo joint venture would build a “fibre-to-the-home” broadband network for 7 million German homes, allowing the British operator to upgrade its existing network in Germany, its largest market.

FibreCo will invest up to €7 billion in the six-year project, which is expected to be 70% financed by debt. Construction will be contracted to Altice’s subsidiary Geodesia, with Vodafone Germany responsible for marketing faster broadband to new customers.

The two companies will own 50% of FibreCo. The collaboration is subject to regulatory approval and is expected to be completed in the first half of 2023. Nick Reed, CEO of Vodafone, said: “This partnership builds on Vodafone’s significant next-generation networks and Altice’s industry expertise and proven fibre-to-the-home build capabilities.”