Shares of

LaBranche

(LAB)

were among the

NYSE's

losers Friday, falling 14% after the specialist firm warned that first-quarter earnings would fall short of expectations.

The company expects earnings of 2 cents to 4 cents a share, well below the 11 cents a share that analysts polled by Thomson First Call had been expecting. The company said that unfavorable market conditions in January, combined with lower volatility and increased program trading during the quarter, led to the weak results. A year ago the company posted earnings of 11 cents a share. LaBranche plans to release first-quarter results on April 27. Shares were trading down $1.37 to $8.49.

Lufkin Industries

(LUFK)

, a Texas-based company that sells oil-field pumping units, rose 11% after the company raised its earnings guidance substantially. The company now expects earnings of 95 cents to $1.05 a share, up from its previous estimate of 65 cents to 85 cents a share. The one-analyst forecast called for earnings of 75 cents a share. Lufkin, which did not offer specific reasons for the earnings beat, said that it plans to release first-quarter earnings on April 20. Shares were trading up $5.43 to $54.20.

Shares of

Constellation Brands

(STZ) - Get Report

rose 8% after the company posted fourth-quarter earnings that were better than expected. Excluding items, the wine and beer distributor posted earnings of $73.2 million, or 62 cents a share, on net sales of $1.04 billion. Analysts were expecting earnings of 58 cents a share on sales of $978.4 million. A year ago the company earned $61.8 million, or 54 cents a share, on sales of 881.3 million. Looking ahead, Constellation forecast first-quarter earnings of 56 cents to 60 cents a share, in line with expectations. Shares were trading up $4.19 to $58.66.

Trex

(TWP)

fell 5% after the company warned that first-quarter earnings would fall below expectations. The maker of composite decking and railing expects earnings of 50 cents to 52 cents a share on sales of $90 million. Analysts had been expecting earnings of 64 cents a share on sales of $89.6 million. A year ago the company earned 63 cents a share on sales of $76.3 million. The higher cost of plastic raw materials and bad weather contributed to the earnings miss. Costs associated with the start-up of two new products also hurt first-quarter earnings. Trex expects to post results on April 27. Shares were trading down $2.13to $42.49.

Shares of

Imax

(IMAX) - Get Report

rose 2% after the company announced another theater deal in China. The new theater system will be installed at a multiplex in Zhengzhou, China, a city of about 2 million people. During the past eight months, Imax has signed contracts for 12 new theater systems in China. In all, Imax currently has plans to open 23 theaters in China that are scheduled to open by 2008. The Imax theater in Zhengzhou is scheduled to open in 2007. Shares were trading up 19 cents to $10.04.

NYSE volume leaders included

Lucent Technologies

(LU)

, up 3 cents to $2.71;

Pfizer

(PFE) - Get Report

, down 34 cents to $26.56;

Time Warner

(TWX)

, up 28 cents to $18.16;

American International Group

(AIG) - Get Report

, down 64 cents to $52.12;

Advanced Micro Devices

(AMD) - Get Report

, up 52 cents to $16.70; and

Emulex

(ELX)

, up 30 cents to $19.30.

Nasdaq

volume leaders included

Intel

(INTC) - Get Report

, up 23 cents to $23.64;

Microsoft

(MSFT) - Get Report

, up 5 cents to $25.15;

Cisco Systems

(CSCO) - Get Report

, down 9 cents to $18.06;

Oracle

(ORCL) - Get Report

, unchanged at $12.45;

Apple Computer

(AAPL) - Get Report

, up 43 cents to $43.99;

Brocade

(BRCD)

, up 9 cents to $5.84.