Geneva ? A two-week U.N. conference reviewing efforts to fight the illegal weapons trade ended in failure Friday, with nations too divided on too many contentious issues to agree on the best way to combat a scourge that fuels conflict worldwide.

After days of negotiations, delegates gave up their bid to agree on an “outcome document” meant to reflect their consensus on the most serious threats and the best way to fight the illegal trade in small arms, worth about $1 billion a year.

The conference was reviewing progress made toward achieving a 2001 program of action to curb the illicit sale of pistols, assault rifles, machine guns and other light weapons.

The global trade in small arms is worth about $4 billion a year, of which a fourth is considered illegal, according to the annual Small Arms Survey, an authoritative report on such weapons. The arms cause 60 percent to 90 percent of all deaths in conflicts every year.