Stocks in the news: Dell, Perot Systems, Lennar, Potash Corp.

Some of the companies making headlines today:

Dell (DELL) said it is acquiring information technology services company Perot Systems (PER) for $3.9 billion, offering $30 per share in cash, a 68 percent premium over Perot's closing share price Friday. PER shares shot up 65 percent in pre-market trading, Dell's fell about 5 percent.

Lennar Corp. (LEN) reported a wider loss in its fiscal third quarter, mostly due to its writedowns of the value of its land and unsold homes. While orders were still down year-over-year, sequentially, they've been on the rise the past few months. Not including the writedowns, the company earned 21 cents per share, handily beating expectations.