17. Inventories

(€ million)

At 31 December 2013At 31 December 2012
Raw materials, supplies and finished goods 8,859 8,160
Assets sold with a buy-back commitment 1,253 952
Gross amount due from customers for contract work 118 183
Total Inventories 10,230 9,295

At 31 December 2013, Inventories increased by €935 million in line with the trend in production and sales volumes for the period in the various markets in which the Group operates. The increase in 2013 is primarily related to the launch of the new models in NAFTA during the last months of the year.

At 31 December 2013, Inventories include those measured at net realizable value (estimated selling price less the estimated costs of completion and the estimated costs necessary to make the sale) amounting to €1,341 million (€1,293 million at 31 December 2012).

The amount of inventory write-downs recognized as an expense during 2013 is €570 million (€634 million in 2012).

The amount of inventories of Chrysler at 31 December 2013 is €4,958 million (€4,200 million at 31 December 2012). Substantially all of the inventories of Chrysler and its U.S. subsidiary guarantors are unconditionally pledged as securities for certain debts of Chrysler (see Note 27).

The amount due from customers for contract work relates to the design and production of industrial automation systems and related products for the automotive sector and can be analyzed as follows: 

(€ million)

At 31 December 2013At 31 December 2012
Aggregate amount of costs incurred and recognized profits (less recognized losses) to date 1,514 1,482
Less: Progress billings (1,608) (1,477)
Construction contracts, net of advances on contract work (94) 5
Gross amount due from customers for contract work as an asset 118 183
Less: Gross amount due to customers for contract work as a liability included in Other current liabilities (Note 29) (212) (178)
Construction contracts, net of advances on contract work (94) 5