Swisscom's second-quarter net profit dropped to 299 million Swiss francs ($244 million) from 596 million francs ($486 million) in the year-earlier period, according to an Associated Press report.
The report said Switzerland's largest telephone company attributed the decline in part to a fine of 180 million francs ($147 million) for overcharging termination fees.
Sales dropped to 2.4 billion francs ($1.96 billion) from 2.47 billion francs ($2 billion) in all of its main business lines, the report said.
"Despite a challenging first half-year 2006, we were once more able to defend our position successfully against our competitors," the company said in a letter to shareholders.
The Associated Press report said Swisscom now expected net earnings of 3.7 billion francs ($3 billion) in the full year, compared with an earlier estimate of around 4 billion francs ($3.2 billion).
The charge followed a decision by a Swiss court to approve price reductions ordered by the Swiss Communications Commission, which said Swisscom had overcharged on certain interconnection services between its fixed line unit and other telecom providers between 2000 and 2003, the report said.