Lufkin Industries ( LUFK) gained after the seller of oil field pumping units and power-transmission products saw its second-quarter earnings rise. Sales climbed 21.4% to $147.7 million. The company posted earnings of $17.5 million, or $1.16 a share, up from $10.4 million, or 71 cents a share, a year ago.

The most recent quarter includes costs of 4 cents a share related to the expensing of stock options. Lufkin raised its third-quarter guidance to a range of $1 to $1.20, compared with 76 cents for the year-ago period. Lufkin also increased its 2006 guidance to a range of $4.17 to $4.57, up from $3.75 to $4.25 previously. Shares were trading up $5.19, or 9.4%, to $60.63.

Keane ( KEA) was climbing following the information technology company's second-quarter earnings report. The company posted income of $9.4 million, or 15 cents a share, up from $7 million, or 11 cents a share, a year ago. Excluding items, the company earned $14.1 million, or 21 cents a share. Revenue totaled $242.6 million, up 2% from a year ago.

Wall Street was looking for earnings of 15 cents on revenue of $245.3 million. Looking ahead, the company forecast third-quarter earnings of 13 cents to 15 cents a share with revenue between $240 million and $250 million. Excluding items, Keane expects earnings of 18 cents to 20 cents a share. Analysts are looking for a profit of 17 cents a share on revenue of $255 million. Shares of Keane gained $1.55, or 13.8%, to $12.76.

LECG ( XPRT) advanced after the company, a provider of economic and financial analysis, expert testimony and litigation support, was upgraded by William Blair & Co. to outperform from market-perform.

Analysts said its confidence in the company's growth outlook has been bolstered, and its valuation has become compelling. As a result, investors should purchase LECG's shares "aggressively," William Blair said. Shares gained $1.85, or 11.6%, to $17.85.

Shares of Denny's ( DENN) tumbled after CL King dropped its rating on Denny's to neutral from strong buy, sending the stock down 41 cents, or 12%, to $3. Volume was about seven times heavier than normal.

Chemicals company Stepan ( SCL) fell after it said second-quarter earnings declined. The company earned $3.1 million, or 31 cents a share, down from $6.2 million, or 64 cents a share, a year ago. Sales increased 5% because of higher selling prices to $292 million.

"The polymer group expects improved volume and earnings in the second half," said F. Quinn Stepan Jr., president and CEO, in a statement. "We have announced price increases to recover continued raw material cost escalation tied to crude oil."

Surfactants earnings should improve in the second half, and fabric-softeners volume will continue to grow, the company said. Biodiesel earnings will also improve over the rest of the year, Stepan predicted. Shares dropped $2.44, or 7.5%, to $29.95.