Warren Buffett's Berkshire Hathaway posted a rare quarterly loss, undercut by Kraft Heinz

Warren Buffett’s Berkshire Hathaway released its fourth-quarter earnings on Saturday, revealing a rare net loss that was battered by its Kraft Heinz holdings.

Although operating profits climbed to $5.72 billion from $3.34 billion (about $3,848 per Class A share) the sprawling conglomerate suffered a $3.02 billion writedown that Buffett said was "almost entirely attributable" to its significant stake in Kraft Heinz. Berkshire owns 325 million shares of Kraft Heinz, making it one of the Omaha, Nebraska-based company's biggest holdings.

The report follows a disclosure by Kraft Heinz on Thursday of a Securities and Exchange Commission investigation into the food and beverage retailer's accounting policies. On Friday, the brand's stock ended at the lowest level in history.

Kraft Heinz dragged on Berkshire, causing it to post a rare share loss of more than $15,000.

Berkshire’s financial reach extends to almost every sector of the economy, and it owns a number of marketable, blue chip-stocks that are valued at $170 billion (excluding the company’s shares of Kraft Heinz). Some of those stocks include Apple, Coca-Cola, Goldman Sachs, Southwest Airlines, American Express and General Motors.

The company also has earning power concentrated in the insurance sector, including Geico, which helped to boost its results.

Buffett also released his widely anticipated annual letter to Berkshire shareholders in which he generally offers insight into general operations at Berkshire; general wisdom and business advice; and stock purchases he made over the year.

This year, Buffett -- as expected -- did not make any significant purchases. The reason? Prices are too high.

"That disappointing reality means that 2019 will likely see us again expanding our holdings of marketable equities," he wrote. "We continue, nevertheless, to hope for an elephant-sized acquisition."

Berkshire ended the year with $111.9 billion pile of cash and equivalents.