MEXICO CITY (Reuters – Monday saw Aeromexico’s creditor object to the Mexican airline restructuring plan. It was arguing that it would unfairly favor majority shareholder Delta Air Lines Inc.

Invictus Global Management stated in a letter addressed to Delta’s board that it had reacted against the Aeromexico plan.

Aeromexico said last week that an unknown third party would tender a valuation of the outstanding shares to it at a fraction (or less) of what they were worth before bankruptcy. This was part of Aeromexico’s efforts to get out of bankruptcy.

Delta would lose 20% of its stake, and Apollo Global Management (NYSE) would take over as Aeromexico’s largest shareholder.

Cindy Chen Delano, Invictus partner, wrote that “daylight must shine upon the actions and decisions which could position you to earn hundreds of millions at the expense of others stakeholders including those who stand economically crushed under Apollo and Delta’s plan.”

The proposal contained “seemingly outrageous financial terms that challenge decades of bankruptcy precedent,” it said.

It said that Invictus was a Delta shareholder and a large creditor to Aeromexico.

Aeromexico claimed it didn’t have any comments, but Delta was not prompt to respond.

Aeromexico saw its shares rise more than 17% just after Monday’s opening. It was regaining some ground from the steep declines following the announcement of their restructuring plan.