NOTE 12 — INTANGIBLE ASSETS

Intangible assets consist mainly of relationships recognized upon business combinations and software development, with application in the management of the business:


			Customer
	Supplier	Software	contracts and
	relationships	development	relationships	Others	Total
Balance as of January 01, 2017	39,726	636,605	615,608	28,002	1,319,941
Foreign exchange effect	—	2,947	3,835	884	7,666
Acquisition	—	37,939	—	—	37,939
Disposal	—	—	(27,652)	—	(27,652)
Amortization	(6,940)	(149,150)	(125,621)	(3,486)	(285,197)
(-) Assets held for sale	—	(37,512)	(25,396)	(17,700)	(80,608)
Balance as of December 31, 2017	32,786	490,829	440,774	7,700	972,089
Foreign exchange effect	—	28,598	77,593	1,243	107,434
Acquisition	—	67,388	—	—	67,388
Disposal	—	(3,791)	(88)	—	(3,879)
Amortization	(6,067)	(167,384)	(130,980)	(2,505)	(306,936)
Balance as of December 31, 2018	26,719	415,640	387,299	6,438	836,096
Foreign exchange effect	—	6,137	12,586	472	19,195
Acquisition	—	100,313	—	—	100,313
Amortization	(5,304)	(157,278)	(116,462)	(3,298)	(282,342)
Balance as of December 31, 2019	21,415	364,812	283,423	3,612	673,262
Estimated useful lives	5 to 20 years	7 years	5 to 20 years	5 years

The composition of other intangible assets by segment is as follows:


	2019	2018	2017
Brazil	238,243	295,107	351,578
Special Steel	132,934	136,910	152,640
South America	1,729	1,441	1,863
North America	300,356	402,638	466,008
	673,262	836,096	972,089