The announcement prompted demands for a parliamentary probe by Finnish opposition leader Anneli Jaeaetteenmaeki.
Next-generation mobile phone services, or 3G, offer high-speed wireless Internet connections and audio and video streaming capabilities.
Jaeaetteemaeki, chairwoman of the Nordic country's second-largest political group, the agrarian Center Party, demanded July 26 that the Parliament investigate what responsibility the government — under Social Democrat Paavo Lipponen — and the Ministry of Industry have in connection with the failed investments.
There is an ongoing debate in Finland over what the state's role in the private sector should be, with the conservative parties favoring privatization.
In the same period as the write-off last year, Sonera had a net income of 678 million euros.
"The write-off was a positive thing, since the benefits related to that are more concrete than possible future profits that might have come," said Matti Riikonen, telecom analyst with Evli Bank in Helsinki.
The market responded positively to the write-offs, with Sonera's share price on the Helsinki Stock Exchange jumping 13 percent to 3.95 euros.
At the height of the tech boom, Sonera's share price almost hit 100 euros.
Last year, Jaeaetteemaeki's predecessor as head of the party, Esko Aho, demanded a probe into the 97 percent fall of Sonera's share price, from 97 euros at the height of the tech boom in February 2000 to just above 3 euros at that time.
If the government had sold its stake in the company when the share-price was at its highest, it would have got rid of two-thirds of the Nordic country's 60 billion euro national debt.
Excluding non-recurring items, Sonera's operating profit for the first half of the year stood at 225 million euros, compared with 56 million euros in the same period in 2001, while revenues were 1.084 billion euros, up from 1.082 euros.
"All in all, Sonera is going in the right direction, operationally the results were good, meeting expectations and even exceeding them in the case of its domestic mobile phone business," Rikkonen said.
In an effort to become a major international mobile phone operator, Sonera invested more than 8 billion euros in European third-generation mobile phone licenses, offering high-speed wireless Internet connections and audio and video streaming capabilities.
It also invested heavily in Turkish, Hungarian and U.S. second-generation GSM operations, amassing a whopping 5.66 billion euros of debt in the process.
Following the downturn in the global economy, Sonera was forced to abandon its third-generation license in Norway, while the Spanish 3G consortium in which it owns a stake was mothballed.
Trouble has since come to its Italian and German ventures, the latter a joint project with Spain's Telefonica. Sonera unexpectedly announced the suspension of the German operations late on July 24.
Through a 1 billion euro share emission and a vast divesting program, where all but its core Nordic operations were retained together with its 3G licenses in Finland, Germany, Italy and Spain, Sonera had cut its debt to 2.142 billion euros by the end of July.
This was seen as crucial for Sonera, because a lower debt level enabled it to get vendor financing for its 3G networks and pave the way for a merger with Sweden's Telia, set for later this year.