Intangible Assets

6 Months Ended

Jun. 30, 2014

Intangible Assets

9. Intangible Assets

The gross book value, accumulated amortization and net book value of intangible assets were as follows:

	(Stated in millions)
	Jun. 30, 2014						Dec. 31, 2013
	Gross		Accumulated		Net Book		Gross		Accumulated		Net Book
	Book Value		Amortization		Value		Book Value		Amortization		Value
Technology/Technical Know-How	$	1,960	$	650	$	1,310	$	1,960	$	597	$	1,363
Tradenames		1,646		290		1,356		1,647		257		1,390
Customer Relationships		2,441		464		1,977		2,263		407		1,856
Other		430		335		95		435		335		100
	$	6,477	$	1,739	$	4,738	$	6,305	$	1,596	$	4,709

Amortization expense charged to income was as follows:

	(Stated in millions)
	2014		2013
Second Quarter	$	86	$	81
Six Months	$	169	$	163

The weighted average amortization period for all intangible assets is approximately 20 years.

Based on the net book value of intangible assets at June 30, 2014, amortization charged to income for the subsequent five years is estimated to be: remainder of 2014—$178 million; 2015—$355 million; 2016—$344 million; 2017—$337 million; 2018—$329 million; and 2019—$318 million.