By Jonathan Stempel (Reuters) -VeriSign shares fell on Tuesday after Warren Buffett's Berkshire Hathaway sold nearly one-third of its stake in the internet infrastructure and domain name registry company for $1.

Here are some of the stories Wall Street is watching on Tuesday, July 29. Warren Buffett's Berkshire Hathaway (BRK-B, BRK-A) is trimming more of its stake in VeriSign (VRSN). Shares of Novo Nordisk (NVO) are being pummeled after warning of a slowdown in sales of its weight-loss drug in the US.

Berkshire Hathaway (NYSE: BRK.A), led by Warren Buffett, has sold about one-third of its stake in internet infrastructure and domain registry company VeriSign (NASDAQ: VRSN). VeriSign announced that Berkshire sold 4.