ROME, July 6 (Reuters) - The difficulties facing Italian banks over their bad loans are miniscule by comparison with the problems some European banks face over their derivatives, Italian Prime Minister Matteo Renzi said on Wednesday.

Italian bank shares have tumbled in recent days and are the worst performers among European lenders this year on investor concerns over how they will handle some 360 billion euros of bad and non-performing loans.

Speaking at a joint news conference with Swedish Prime Minister Stefan Lofven, Renzi said other European banks had much bigger problems than their Italian counterparts.

“If this non-performing loan problem is worth one, the question of derivatives at other banks, at big banks, is worth one hundred. This is the ratio: one to one hundred,” Renzi said. ($1 = 0.9021 euros) (Reporting by Isla Binnie; Editing by Crispian Balmer)