Bouygues Telecom posted a return to profit in 2016, finishing €83 million in credit, a €142 million swing from a year ago, when it posted a full-year loss of €59 million.
It recruited one million more mobile customers in the period, a year ahead of schedule, on the back of heavy investment in LTE infrastructure, it said.
Total sales for the year increased six percent, to €4.8 billion, compared with a two percent rise a year ago.
The operator said mobile sales were up five percent on 2015, compared with a decline of five percent a year ago.
EBITDA rose €164 million to €916 million, with its margin 23 percent higher than in 2015.
The France-based operator added 1.1 million mobile customers in 2016, excluding M2M customers, and 335,000 in the final quarter.
As its total mobile base hit 13 million at the end of the year, Bouygues said it was a year ahead of its target on new customer acquisitions.
Almost two thirds (65 percent) of its mobile customers now take 4G services; data usages hit 4.2GB per user in December, up from 2.5GB a year ago.
Meanwhile, it gained 313,000 fixed broadband customers in 2016, including 98,000 in the final quarter, for a total base of 3.1 million s at end of December.
FTTH accounted for 26 percent of net growth.
The company said it will invest €1.2 billion in LTE and FTTH infrastructure this year, with particular focus on LTE network densification.
Last year, Bouygues Telecom sold 230 mobile towers to Spain-based Cellnex as part of a long-term partnership between the two companies.
It said the Cellnex sale resulted in a €104 million capital gain during 2016.