What is negative goodwill? How is it reported in the consolidated balance sheet?

Negative Goodwill.

After you allocated the PD to your share of the FMV increase of all the net assets/liabilities, your amount is not a positive (positive Goodwill), but rather a negative amount.

It does NOT appear on the balance sheet. Well, in a way it does. Negative Goodwill is prorate over your non current and non financial assets (so pretty much you intangibles and PPE), so the negative goodwill would end up lowering those asset values on the consolidate balance sheet.