CLEVELAND, Ohio — Investors who still own stock in Cleveland-based Cliffs Natural Resources face another round of bad news.

Their stock lost more than 12 percent of value Tuesday, closing at just $2.38 a share on the New York Stock Exchange, after two investors who previously bought unsecured bonds in the company filed a class action lawsuit.

The complaint, filed in a federal court in New York, alleges that Cliffs, still the nation’s larges iron ore mining company, gave big institutional bondholders and banks an opportunity to exchange their unsecured Cliffs notes for new unconditionally guaranteed notes that pay an 8 percent rate of  interest and come due in 2020.

The deal “created two classes of holders of Class Notes with very unequal rights,” the suit alleges, adding that individual bondholders “were kept in the dark regarding the …[ details of the company’s] exchange offer.”

What this means, says the suit, is that holders of the new notes would come first if the company had to choose whom to pay, for example in a bankruptcy proceeding.

The exchange of the old notes for the new bonds has “impaired the Class members’ [those holding the old notes] right to received payment of the principal and interest … and the right to institute suit to compel such payment,” the suit argues.

Cliffs on Tuesday issued the following statement without further comment:

“Cliffs typically does not comment on litigation matters. However, the company felt compelled to state its belief that this lawsuit over the note exchanges in January 2016 is entirely without merit. Cliffs fully intends to defend vigorously against the claims.”

The sell-off of Cliffs shares Tuesday came right on the heels of a 16 percent surge in the company’s share price Monday on news that it would restart iron ore production in Minnesota by mid-May. The restart decision came after the Commerce Department said it would impose tariffs on imported steel.

And the exchange deal itself helped push Cliffs’ share price up in February because the point of the exchange was to reduce the company’s debt as it weathers the global decline in steel making and demand for iron ore.

In the past five years, the value of Cliffs’ stock has fallen from about $100 a share in the spring of 2011 to $2.71 on Monday, before losing another 33 cents to close at $2.38 a share Tuesday.