Buffett's Berkshire trims U.S. Bancorp stake

Warren Buffet's Berkshire Hathaway $伯克希尔-B(BRK.B.US)$, $伯克希尔-A(BRK.A.US)$ sells a fraction of its holdings in U.S. Bancorp $瑞银(UBS.US)$, according to an SEC filing.
Berkshire sold just under 500K USB shares, bringing the firm's holdings to 150.5M.
Likely the sales are intended to bring Berkshire's stake in USB to below 10%.
In late April, the Oracle's stake rose to over 10% of public float after USB bought back shares.