Warren Buffett’s Berkshire Hathaway this morning announced that it has agreed to acquire Precision Castparts PCP 19.19% , a Portland, Ore.-based maker of aircraft components, for around $37.2 billion in cash. The $235 per share deal represents a 21.2% premium over Friday’s closing price for Precision Castparts stock. Berkshire Hathaway already owns around 3% of Precision Castparts stock.

It is the second-largest acquisition ever by Berkshire Hathaway BRK.A -0.15% , following its purchase of BNSF Railway in 2010. That deal was for $36 billion (including $10 billion of assumed debt), at an enterprise value of $44 billion (Buffett already held a sizable piece of the company). Its most recent mega-deal was the $36 billion billion purchase of Kraft Foods by Heinz, which is backed by both Berkshire and private equity firm 3G Capital.

If you did not include any assumed debt, then this would be Berkshire’s largest acquisition of all time.

Reports of the deal first leaked over the weekend, as is typical in a major Buffett transaction. Here was some of what Fortune‘s Steve Gandel wrote yesterday:

Precision’s highly specialized parts for airplane makers gives the company a “business moat,” a protection from competitors, that Buffett has said he looks for. The company gets 70% of its $10 billion in revenue from the aerospace industry, as airlines have ramped up demand for fuel-efficient jets. The acquisition is also a bet on the improving finances of the newly consolidated airline industry and the economy in general, which Buffett has long been positive on. For Precision, which has recently done a number of small acquisitions and plans to continue, the Berkshire acquisition will give it access to Buffett’s large checkbook.

Buffett told CNBC this morning that he first made the “high multiple” bid during last month’s Allen & Co. conference in Sun Valley, and that the recent “slump in oil and gas” may have helped his cause.

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