The French government's borrowing costs have surpassed Spain's for the first time in almost 18 years as investors worry about France's yawning public deficit.
The yield, or interest rate, on 10-year French sovereign bonds reached 2.94% in early afternoon deals compared to 2.93% for the Spanish equivalent.
The last time Spain paid less than France, the European Union's second-biggest economy, to borrow money was in November 2006.
Spain was among southern European countries at the heart of the euro zone debt crisis more than a decade ago, which forced them to enact austerity measures.
More recently, Spain's economy is growing at a much faster pace than those of France and Germany.
The French public deficit could exceed 6% of national output this year - double the limit set by the European Union.
Newly appointed French Finance Minister Antoine Armand said it was "one of the worst" deficits in the country's modern history.
The political situation in France has also made investors nervous since President Emmanuel Macron called a snap election that left no party with an outright majority after the second round of voting in July.
A new government, led by conservative Prime Minister Michel Barnier, was appointed only on Saturday.
