#10 Navistar International
Ticker: NAV
YTD stock performance: -45%
Market cap: $1.8 billion
Fortune 500 rank: 193

Analysts at Morningstar have a name for the problems affecting leading truck maker Navistar (NAV, Fortune 500): "Engine troubles."

The company has traditionally enjoyed close to a 50% market share in the school bus and medium-duty truck markets, but it made a major misstep when it chose to pursue a different type of engine than the rest of the industry. With $700 million spent on research and development, Navistar placed a huge bet on an engine technology called exhaust gas recirculation. It lost badly. The result of years of development was a product that didn't meet EPA emissions requirements, forcing the company to abandon the technology this year.

Recently, Navistar successfully raised capital to get new, compliant engines, but not before the stock tanked and market share fell from 31% to 21%. Now, the CEO is out and there are new board members. Could this mark the start of a turnaround? Analysts at JP Morgan like the "clean slate approach." But Morningstar warned of "irreparable harm to Navistar's market share."

Source: CNNMoney
Data as of Dec. 7 market close, provided by S&P Capital IQ
  @FortuneMagazine - Last updated December 21 2012 02:35 PM ET
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