"Today's agreement is a landmark," WTO Director General Roberto Azevedo said in a statement, describing the accord as "the first major tariff cutting deal" at the organisation in 18 years.
The deal covers more than 200 products worth about USD 1.3 trillion in annual global trade.
The products account "for approximately 7 percent of total global trade today.
"This is larger than global trade in automotive products - or trade in textiles, clothing, iron and steel combined," the WTO said.
The deal is an expansion of a pact reached in 1996 by 81 WTO members, known as the Information Technology Agreement (ITA).
In 2012, member states resolved that new terms for the ITA were needed because innovation had advanced so dramatically.
But there were considerable hurdles to striking a broader agreement, notably differences between the United States and China.
In November of last year, President Barack Obama said in Beijing that the two sides had "reached an understanding" on moving the talks forward.
