The new calculation is based on profit-and-loss balance sheets instead of Grifols' usual financial reporting model, which uses so-called alternative performance measures.

In Thursday's filing, Grifols said its leverage ratio according to profit-and-loss accounting was 8.4 times in 2022 and in 2023, compared to the ratios of 7.1 and 6.3 times, respectively, it had earlier reported under its credit agreement.

CNMV asked Grifols on March 21 to publish within 15 days a breakdown of its 2022 and 2023 consolidated earnings before EBITDA and the financial debts of entities in which it had non-controlling interests.

Since early January, short-sheller Gotham City Research released three reports accusing Grifols of overstating earnings and understating debt. Grifols' market value has shed billions of euros since then.

Gotham City questioned Grifols' reported EBITDA and leverage ratio of 6.7 times in the third quarter of 2023. It said the ratio was close to 10 to 13 times EBITDA.

The supervisor's investigation found no significant errors in the amounts Grifols reported but identified "deficiencies in the detail and accuracy of breakdowns and explanatory notes in some years".

The company said on Thursday that the difference between the ratios was due to the inclusion in its 2023 EBITDA calculation of adjustments for extraordinary, unusual or non-recurring expenses and for cost savings and operational improvements for the next 12 months.

Before, it reported an EBITDA of 1.48 billion euros ($1.61 billion) for 2023. The new calculation showed an EBITDA of 1.25 billion euros in the same period.

The other reason for the discrepancy was the exclusion of finance leasing related to plasma donation centers as part of debt in accordance with the credit agreement it signed with lenders, it added.

Grifols pledged to disclose the consolidated EBITDA ratios according to profit and loss and adjusted EBITDA in future earnings reports so that "investors have all the information available".

($1 = 0.9211 euros)

(Reporting by David Latona and Jesús Aguado; Editing by Cynthia Osterman)