8 Other financial assets

millions of €
  Dec. 31, 2017 Dec. 31, 2016
  Total Of which: current Total Of which: current
Originated loans and receivables 3,507 3,015 5,664 5,104
Available-for-sale financial assets 4,216 8 5,548 13
Derivative financial assets 1,317 306 2,379 594
Held-to-maturity investments 5 8 2
  9,045 3,329 13,599 5,713
millions of €
  Of which: Of which: not impaired on the reporting date and past due in the following periods
Originated loans
and receivables
neither impaired
nor past due on the
reporting date
Less than 30 days Between
30 and 60 days
Between
61 and 90 days
Between
91 and 180 days
Between
181 and 360 days
More than 360 days
As of Dec. 31, 2017              
Due within one year 2 933 23 3 1 3
Due after more than one year 333
               
As of Dec. 31, 2016              
Due within one year 4 620 63 87 8 1 3 2
Due after more than one year 404

The decline of EUR 2.1 billion in current originated loans and receivables was mainly attributable to the utilization of a cash deposit of EUR 2.0 billion placed with the U.S. telecommunications authority in June 2016 in connection with the spectrum auction concluded in the second quarter of 2017. The reduction of EUR 1.3 billion in the carrying amount of available-for-­sale assets primarily relates to a total impairment equivalent to EUR 1.5 billion (2016: EUR 2.2 billion) of the stock exchange-traded financial stake in BT recognized in profit and loss in 2017.

With respect to the originated loans and receivables that are neither ­impaired nor past due, there are no indications as of the reporting date that the debtors will not meet their payment obligations.

Receivables of EUR 504 million (December 31, 2016: EUR 235 million) were used in connection with collateral agreements as surety for potential credit risks arising from derivative transactions.

Available-for-sale financial assets in the amount of EUR 187 million were recognized at cost as of December 31, 2017 
(December 31, 2016: EUR 126 million). No plans existed as of the reporting date to sell these instruments.