U.S. trucker YRC posts smaller loss but shares fall

Troubled U.S. trucker YRC Worldwide Inc reported a narrower second-quarter loss on Tuesday and said "significant operating momentum" would drive improvements through the rest of the year.Shares dropped nearly 15 percent, however, as the carrier, which narrowly averted bankruptcy last December, said it still faced many challenges.Last December, YRC, the largest U.S. trucking company handling