Johann Rupert, the billionaire who controls luxury-goods giant Richemont, is considering selling stakes in two South African fibre networks valued at as much as $1.5-billion, people with knowledge of the matter said.

The tycoon is working with an adviser to gauge interest from potential investors in buying stakes in Vumatel and Dark Fibre Africa, according to the people, who asked not to be identified because the information is private. Bidders could include local telecommunications companies as well as infrastructure funds, the people said.

Vumatel helped pioneer the country’s fibre-to-the-home industry, while Dark Fibre operates over 10 000 km of high-speed network infrastructure. Rupert owns his stakes in the two companies through Community Investment Ventures Holdings, a unit of his publicly traded investment firm Remgro.

A representative for Community Investment Ventures said the company is in the early stages of raising “a significant amount of primary equity” from local investors. It’s also in talks with South African financial institutions about refinancing its senior debt. The exercise has attracted “marked interest” and will position the group for long-term growth, according to the statement.

Deliberations are at an early stage, and details such as the potential valuation could change, the people said. The companies could also consider an eventual stock market listing, the people said. A representative for Remgro declined to comment, while representatives for Dark Fibre and Vumatel didn’t immediately respond to requests for comment.

Households in cities including Johannesburg, Cape Town and Durban are increasingly seeking higher speeds and more capacity to handle rising consumption of data for services including video streaming. Vumatel, which entered the market in 2015, runs an open-access network that lets internet providers offer services using its lines.

Community Investment Ventures acquired 35% of Vumatel last year. It took full control of the company in May, according to Remgro’s annual report. Community Investment Ventures owns about 51% of Dark Fibre Africa, the company’s website shows.

Rupert’s family has an estimated net worth of $7.1-billion, making him South Africa’s richest person, according to the Bloomberg Billionaires Index. He is chairperson of Richemont, the Swiss company that owns brands including Cartier and Van Cleef & Arpels.