One of the most anticipated and closely scrutinized regulatory documents has been filed: Berkshire Hathaway's (BRK.A -0.10%) (BRK.B -0.09%) 13F. This is the quarterly breakdown of the Warren Buffett-led company's considerable holdings in publicly traded companies.

As ever, at the end of the first quarter, the constantly shifting Berkshire portfolio saw some changes from the preceding quarter, several of which were quite dramatic. On the whole when making a quarter-over-quarter comparison, the company did more selling than buying.

Warren Buffett.

Image source: The Motley Fool.

For instance, the company revealed in the filing that has entirely liquidated its approximately $700 million position in store credit card specialist Synchrony Financial.

Elsewhere in the financial sector, Berkshire drastically trimmed its stake in one of its more classic investments, Wells Fargo. Its position declined to just over 675,000 shares, from the previous quarter's tally of nearly 52.5 million.

Several positions in other sectors were also cut. The pharmaceutical sector saw a set of chops, as Berkshire reduced stakes in AbbVie, Merck, and Bristol Myers Squibb. Meanwhile, the company reduced its General Motors position, and those of energy giant Chevron and satellite radio king Sirius XM Holdings.

On the other hand, Berkshire significantly ramped up its investment in supermarket chain operator Kroger, boosting its position by 52% to over 51 million shares. Another notable addition was the roughly 12 million shares in the company's Verizon Communications stake; this stood at 159 million shares at the end of the first quarter.

One new investment for Berkshire during the quarter was in insurance company Aon, with a relatively modest stake of 4.1 million shares.

Meanwhile, two of the larger Berkshire positions -- those of Bank of America and Apple -- remained unchanged.

As neither Buffett nor Berkshire itself typically comments on its 13Fs, the reasons for their various adjustments were not immediately apparent.