The only truly new position in Berkshire Hathaway's portfolio last quarter was Chicago Bridge & Iron ( CBI), a $6.8 billion construction and engineering firm that, despite its Windy City name, is actually domiciled in the Netherlands. Buffett and company took on a 6.51 million share position in CBI last quarter, which works out to a $404 million grubstake at current price levels. That ownership represents 6.03% of CBI's total market value -- a substantial position indeed. >>5 Stocks Set to Soar on Bullish Earnings CBI is a worldwide engineering and construction firm. The firm's specialty comes in constructing energy facilities around the globe -- but it's got a particular niche in building facilities that handle liquefied natural gas. Around 20% of CB&I's sales come from building steel plate structures that industrial customers use to store material. That hefty energy sector and industrial exposure has some consequences, both good and bad; most importantly, it means that the firm benefits when commodity prices are high and energy firms are investing heavily in infrastructure projects. In recent years, CB&I has begun reaching away from its core construction and engineering business, adding on new ways to service its existing petrochemical customers. The Lummus Technology unit, for instance, sells gas processing and refining technology. While it's still a small chunk of CBI's revenues, it's a lucrative one. The recently closed $3 billion acquisition of Shaw Group adds considerable nuclear building expertise to CBI's offerings. That's attractive positioning to own as power companies invest in low-cost power generation.