ROME — Talks between two anti-establishment parties to form a new Italian government seemed to be regaining momentum on Wednesday, even as financial markets were spooked by leaked documents that suggested the two sides shared a desire to radically change Italy’s relationship with the European Union.

The leaders of the Five Star Movement and the anti-immigrant League party dismissed the leaked document Tuesday night as “old.”

But the draft, which was on the negotiating table as of Monday morning, was apparently not “old” enough to avoid raising jitters. On Wednesday, investors shed Italian assets, and shares trading on the Milan stock market slipped.

Current or not, the document, obtained by Huffington Post Italy, brought into focus concerns among European leaders and financial markets about what a government run by the two parties could mean for Italy and the European Union as a whole.