Mobile phone companies are struggling to meet a government deadline for them to list their shares on the local market by the end of the year, industry sources said, leaving them facing the prospect of being fined or having their network operating licences suspended.

The country's eight operators are required by law to have 25 percent local ownership by Dec. 31. They include Vodafone subsidiary Vodacom, Millicom subsidiary Tigo, and a local unit of India's Bharti Airtel.

President John Magufuli, elected to office last year, has said the move will bring more transparency and offer the public a share in the industry's profits. But analysts say rushing through public offerings could lead to unsold shares, given that only Tanzanians are allowed to buy them. Meanwhile mining firms face a longer two-year deadline to sell 30 percent of their shares on the local market.

"The Magufuli administration has a lot of good intentions but it is one thing to announce a policy and a totally different ball game when it comes to implementation," said Ahmed Salim at global advisory Teneo Intelligence.

"There's a lack of realism." The Dar es Salaam Stock Exchange has a market capitalisation of $9.3 billion, while Salim has estimated that the total market capitalisation for all the telecoms firms amounts to $2.5 billion.

Listing stakes in the firms by the end of 2016 could overwhelm the market, where officials say annual turnover is $1 billion, leaving offerings undersubscribed. Although foreigners are allowed to buy listed shares, the telecoms law restricts buyers in the new listings to Tanzanians.

The law to list 25 percent stakes was passed in 2010 but went unheeded until Magufuli ordered its implementation this year, surprising many telecoms firms. The stock exchange's chief executive, Moremi Marwa, said three companies had asked for listing guidance.