Updated from 12:35 p.m. EDTAlcan (AL) - Get Air Lease Corporation Class A Report was among the NYSE's winners Monday, as shares soared 34.5% after the aluminum producer received an unsolicited buyout offer from rival Alcoa (AA) - Get Alcoa Corp. Report.

The offer is worth almost $27 billion, or $73.25 a share, representing a premium of 20% over Alcan's closing price of $61.03 on Friday. Alcoa said the offer comes after nearly two years of discussing possible business combinations with Alcan. Alcan said it would consider the proposal. Shares of Alcan closed up $21.08 to $82.11. Shares of Alcoa closed up $2.97, or 8.3%, to $38.63.

Armor Holdings

(AH)

rose 5.4% after the military contractor agreed to be acquired by

BAE Systems

for $4.1 billion, or $88 a share in cash. The price represents a 7% premium over Armor's closing price of $82.15 on Friday. "We are exceptionally pleased to join forces with BAE Systems plc, a global leader in the defense industry," Armor Holdings said. The acquisition is expected to close during the third quarter. Shares of Armor closed up $4.45 to $86.60.

Shares of

Ohio Casualty

( OCAS) vaulted 29.6% after the insurance company agreed to be acquired by privately held

Liberty Mutual

for about $2.7 billion, or $44 a share. The all-cash deal represents a premium of 32% over Ohio's closing price of $33.32 on Friday. The deal is expected to close during the third quarter. Shares of Ohio Casualty closed up $9.85 to $43.17.

Tetra Technologies

(TTI) - Get TETRA Technologies, Inc. Report

fell 3% after the oil and gas services company posted lower-than-expected first-quarter earnings. The company reported earnings of $20.7 million, or 28 cents a share, on revenue of $247.7 million. Analysts expected earnings of 32 cents a share on revenue of $232 million. During the year-earlier quarter, the company earned $19.5 million, or 26 cents a share, on revenue of $151.3 million. Shares closed down 80 cents to $25.96.

Shares of

Hansen Natural

( HANS) traded actively after the beverage maker posted a first-quarter sales shortfall. The company reported net sales of $165.4 million, below the $167.9 million that analysts expected. During the year-earlier quarter, the company posted sales of $119.7 million. Hansen did not release earnings because it is still working on filing its delinquent financial reports with the

Securities and Exchange Commission

. Shares slid 2.7% earlier in the day but closed up $1.10, or 2.8%, at $40.42.

NYSE volume leaders included

Constellation Brands

(STZ) - Get Constellation Brands, Inc. Class A Report

, up 52 cents to $23;

Motorola

( MOT), which closed flat at $18.08;

General Electric

(GE) - Get General Electric Company (GE) Report

, up 9 cents to $37.24;

Boston Scientific

(BSX) - Get Boston Scientific Corporation Report

, up 51 cents to $16.67;

AT&T

TheStreet Recommends

(T) - Get AT&T Inc. Report

, up 12 cents to $39.60;

Pfizer

(PFE) - Get Pfizer Inc. Report

, up 30 cents to $27.38; and

Time Warner

(TWX)

, up 43 cents to $21.72.

Nasdaq

volume leaders included

Yahoo!

(YHOO)

, down 60 cents to $30.38;

Microsoft

(MSFT) - Get Microsoft Corporation (MSFT) Report

, up 15 cents to $30.71;

Cisco Systems

(CSCO) - Get Cisco Systems, Inc. Report

, down 10 cents to $27.81;

Level 3 Communications

(LVLT)

, down 6 cents to $5.54;

Marvell Technology Group

(MRVL) - Get Marvell Technology Group Ltd. Report

, up 20 cents to $17.80;

Dendreon

(DNDN)

, down $1.47 to $17.92;

Sun Microsystems

(SUNW) - Get Sunworks, Inc. Report

, down 2 cents to $5.22; and

Intel

(INTC) - Get Intel Corporation (INTC) Report

, up 6 cents to $21.96.