French digital infrastructure investor Antin Infrastructure (EPA: ANTIN) has reportedly begun the process to sell Spanish fibre owner and operator Lyntia which could rank up more than €4 billion (US$4.3 billion).

Citing unidentified market sources, national newspaper Expansión wrote the sale is set to take the form of an auction and will take place in mid-January.

Amongst the potential buyers are Cellnex (BME: CLNX) and American Tower Corporation (NYSE: AMT), which has recently acquired US-based data centre operator CoreSite for $10.1 billion.

Advisors to the sale include Banco Santander, Deutsche Bank and UBS, the sources said.

Lyntia’s fibre business operates under two different brands, a nationwide wholesale fibre backbone operation, and local fibre access networks, including lit and unlit fibre, and FTTH connectivity.

Combined, the two business arms amount to more than 41,500 Km of fibre networks, 59,476 on-net buildings and in 97,730 near-net buildings in the main big cities in Spain to provide services to a total of 2,694 connected towns and cities.

In addition, the company has connections with major underwater cable landing stations in the Iberian Peninsula and interconnections with France and Portugal.

According to Expansión, the two divisions – Lyntia Access and Lyntia Networks – are posed to be sold separately, however, it is possible that a single buyer could snap up both.