Stocks that moved substantially or traded heavily Friday on the New York Stock Exchange and Nasdaq Stock Market. Data from the Associated Press:

NYSE
Upticks,downticks Southern Union Co., up $5.70 at $39.85
Williams Cos. Inc. announced a $4.9 billion bid to buy the gas pipeline company, topping an earlier offer from rival Energy Transfer Equity. Southern Union is the parent of Missouri Gas., which serves the Kansas City area.

STR Holdings Inc., down $2.39 at $14.33
The maker of solar module products cut its second quarter earnings and revenue forecasts on weaker demand in certain countries.

United Continental Holdings Inc., down $2.15 at $22.99
The operator of United Airlines and Continental Airlines issued a second-quarter outlook that was lower than what analysts had expected.

Discover Financial Services, up 90 cents at $24.79
Shares of the credit card issuer rose a day after the company said its profit more than tripled in the second quarter.

Nasdaq
Blackboard Inc., up $3.17 at $43.94
The Wall Street Journal reported that Providence Equity Partners is nearing a deal to acquire the educational software provider.

Majesco Entertainment Co., up 11 cents at $2.96
The maker of the “Cooking Mama” and “Zumba Fitness” video games said its stock will be added to the Russell Microcap Index.

Micron Technology Inc., down $1.22 at $7.21
The chipmaker reported third-quarter results that missed analyst estimates as sales of the company’s chips fell.

Pain Therapeutics Inc., down $3.94 at $5.30
Regulators rejected the biopharmaceutical company’s pain drug Remoxy, which was developed in partnership with Pfizer and Durect.