How should FX pertaining to a foreign-denominated subsidiary that is held for sale be accounted for by the parent on a US GAAP consolidated basis?

The foreign subsidiary continues to be consolidated following ASC830 rule set so the gain/loss continues to be recorded in CTA for the period the subsidiary is for sale. The "long-term investment" language relates to the recording of fx gains and losses on intercompany receivable/payable and the subsidiaries intent to repay the loan. If they can't/won't repay the loan if the sale doesn't happen then those changes, too, would continue to revalue to CTA. Upon the sale the CTA will factor into the gain/loss on the transaction.

So yes, the parent would continue to show CTA due to translation. I don't understand the question on the gain/loss on standalone entity surviving consolidation. Is it stand alone or consolidated?

Thanks Helen! The parent has standalone reporting requirements, so I was essentially looking for answers to several questions. First, and foremost, the treatment of FX gains/losses resulting from translation (not remeasurement) of a Euro-based foreign subsidiary that is being held for sale up to USD parent consolidated reporting under US GAAP. I believe you answered that question in your first sentence and I thank you.

Second, for parent standalone reporting, ASC 323-10-35-4 and 35-5 (i.e., equity method investment accounting) tells us that adjustments to the parent's investment in the investee (in our case, 100% ownership of a foreign subsidiary) should flow through earnings. ASC 323-10-35-18 further states that adjustments resulting from changes in the investee's OCI (e.g., foreign currency items) should also be reflected in the parent's investment in foreign subsidiary account with "corresponding adjustments in equity." So for parent standalone reporting, does this mean there would be an FX component, similar to CTA on the subsidiary's books, within the parent's OCI line? In other words, how should changes in FX stemming from the Euro-denominated investment in foreign subsidiary be accounted for on the parent's standalone books?

The part about the "long-term investment" was, by analogy, my originally thoughts on how to treat a foreign-denominated investment in sub on the parent's standalone books (i.e., remeasure FX gain/loss through P&L with gain/loss surviving consolidation). But I think I'm beyond that point now after revisiting ASC 323.

Any further insight into this matter would be greatly appreciated!

Yes, the changes in value of the foreign functional subsidiary related to FX and identified in the consolidation process (all assets and liabilities at current rate and equity at historical) belongs in CTA/OCI on the parent's books.