France Telecom has seen its debt rise by 6bn euros ($7.7bn; £4bn) to 49.9bn euros, as it conforms to new accounting rules.
France Telecom is one of the world's most indebted telecoms firms
The company said the move to International Financial Reporting Standards (IFRS) would not impact its ongoing operating performance.
One of the world's most indebted telecoms firms, it is in the third and final year of a recovery plan.
France Telecom wants to reduce its debts to less than 40bn euros by 2006.
The firm, which owns mobile phone group Orange, built up its vast debts due to an ambitious expansion plan in the late 1990s.
Harmonised tax rules
France Telecom - Europe's third-largest telecoms firm - saw its debt peak at 68bn euros in 2002.
This latest figure of 49.9bn euros applies to the year ending 31 December 2004.
Under IFRS rules, its 2004 operating profit has been reduced to 9.3bn euros from 10.8bn euros previously.
Publicly-listed companies in Europe began the switch to IFRS at the start of this year.
The aim of the new rules is to harmonise the global presentation of financial results, making it easier to compare companies across borders.