Montreal, Canada

Not everyone is making a killing amid $1,370 gold.

Several international mid-cap gold mining producers continue to struggle in this historical bull market for the yellow metal. Output has been cut at several companies in Africa and Russia this year as a host of production bottlenecks cut earnings forecasts.

And therein lies an opportunity for investors seeking an undervalued mining play as gold stocks hit new highs recently.

African Barrick Gold (ABGLF.PK), which went public last March at 575 pence on the London Stock Exchange, continues to struggle and just revised its gold production lower for the second time this year. The company has been a victim of local fuel theft by organized crime at its Buzwagi mine in Tanzania.

Theft of fuel intended for transportation trucks and mining equipment has hampered production at African Barrick’s main mine in Tanzania; last week, the company cut its forecast by 30,000 ounces – the second cut since March. The stock thereafter tanked more than 9%, hitting a new post-IPO low of 564 pence or $9 a share.

African Barrick Gold was floated by its parent company, Barrick Gold in Toronto, Canada. Barrick Gold (ABX-NYSE) is one of the largest gold mining companies in the world.

Other gold mining companies listed are also taking hits, despite record gold prices in 2010.

Russian-based Petropavlovsk (POG-London) plunged 26% during the first six months of the year and South African-based Rangold Resources (GOLD-NASDAQ) is also struggling with mining production delays in Mali, close to the Senegal border.

Among the North American-listed laggards in the ongoing rally, Kinross Gold (KGC-NYSE) and Yamana Gold (AUY-NYSE) are my favorites at these prices. Both stocks have badly trailed the XAU Gold Index since January and offer good value at these levels. Also, unlike foreign operators like African Barrick, AUY and KGC don’t have to contend with potentially rogue workers or hostile political environments at flagship mining operations.