Shares of

Sallie Mae

(SLM) - Get Report

were among the

NYSE's

biggest winners Friday, jumping 11% after a media report said the student loan lender is in talks to be acquired for more than $20 billion.

The New York Times

reported that Sallie Mae is discussing a buyout with a group of private equity firms, including Blackstone Group. The negotiations appear to be at a late stage, but several hurdles remain, the paper reported. Shares of Sallie Mae recently were trading up $4.51 to $45.26.

Shares of

Lubrizol

( LZ) jumped 8% after the maker of engine oil previewed first-quarter earnings that were well above expectations. The company put its adjusted earnings at 98 cents a share. Analysts project earnings of 78 cents a share. A year earlier, the company posted adjusted earnings of 68 cents a share.

"The strong performance compared to the first quarter a year ago was primarily the result of higher revenues, driven by the improvement in the combination of price and product mix," Lubrizol said. "In addition, shipment volumes in the quarter were higher than expected, and reflected a return to normal order patterns." Shares were trading up $4.50 to $57.74.

General Electric

(GE) - Get Report

climbed 1% after the conglomerate posted in-line first-quarter earnings and better-than-expected revenue. The company earned $4.51 billion, or 44 cents a share, on revenue of $40.2 billion. Analysts polled by Thomson First Call expected earnings of 44 cents a share and revenue of $39.8 billion. In the year-earlier quarter, the company earned $4.18 billion, or 40 cents a share, on revenue of $38 billion.

Looking ahead, General Electric forecast second-quarter earnings of 52 cents to 54 cents a share, in line with the 53 cents a share that analysts project. Shares were up 27 cents to $35.45.

Shares of

FCStone Group

( FCSX) rose 9% after the commodity-risk-management concern posted big gains in second-quarter earnings and revenue. For the quarter ended Feb. 29, the company reported earnings of $6.9 million, or 48 cents a share, on revenue of $403.4 million. During the year-earlier quarter, the company earned $3.9 million, or 27 cents a share, on revenue of $268.9 million. Shares of FCStone, which went public just a month ago, were adding $3.44 to $39.38.

Varian Medical Systems

(VAR) - Get Report

slid 8% after the medical equipment maker warned that second-quarter revenue would be below Wall Street's forecast. The company estimates revenue growth of about 7% for the recently ended quarter. That suggests revenue of about $442.9 million, below analysts' estimate of $454.3 million.

Varian expects earnings to come in slightly ahead of its previous forecast of 46 cents a share. Analysts project earnings of 45 cents a share. Shares were trading down $4.01 to $44.93.

NYSE volume leaders included

Merck

(MRK) - Get Report

, up $3.65 to $50.01;

Pfizer

(PFE) - Get Report

, up 31 cents to $26.77;

Advanced Micro Devices

(AMD) - Get Report

, down 24 cents to $13.42;

Ford

(F) - Get Report

, down 5 cents to $8.04;

Kraft Foods

( KFT), up 1 cent to $32.46;

Exxon Mobil

(XOM) - Get Report

, up 5 cents to $77.44;

Time Warner

(TWX)

, up 18 cents to $21.18; and

Motorola

( MOT), up 1 cent to $17.53.

Nasdaq

volume leaders included

Dyax

(DYAX)

, up $2.26 to $6.26;

Sirius Satellite Radio

(SIRI) - Get Report

, up 4 cents to $3.12;

Sun Microsystems

(SUNW) - Get Report

, down 7 cents to $5.83;

Intel

(INTC) - Get Report

, down 14 cents to $20.36;

Applied Materials

(AMAT) - Get Report

, down 36 cents to $18.99;

Apple

(AAPL) - Get Report

, down $1.10 to $91.09; and

Microsoft

(MSFT) - Get Report

, down 14 cents to $28.40.