Updated from 11:28 a.m. ET

Lehman Brothers

initiated coverage of the Internet security sector Thursday, saying it expects it to be among the "best performing sectors in technology" in the next one to two years.

"In order for the Internet to achieve its vast commercial potential, we believe that a comprehensive security infrastructure must exist in order to establish the requisite level of trust and confidence for conducting large scale business transactions online," the firm wrote in a research note. It expects the Internet security software market to reach $13.3 billion by 2004.

Lehman said this sector should "experience rapid growth" because of concerns over Internet security, strong industry fundamentals, an increase in corporate security budgets and little evidence of a slowdown in spending in the sector. It said the sector should benefit from a long period of sustained growth that is independent of economic cycles.

The firm initiated coverage of

Check Point

(CHKP) - Get Report

and

Internet Security Systems

(ISSX)

, both with strong buy ratings. It started coverage of

RSA Security

(RSAS)

and

VeriSign

(VRSN) - Get Report

with buy ratings, and

Network Associates

(NETA)

,

Symantec

(SYMC) - Get Report

and

Entrust Technologies

(ENTU)

with market perform ratings.

Shares of Check Point leaped $7.13, or 7.9%, to $97.31, and Internet Security Systems jumped $7.25, or 10.6%, to $75.81 in recent

Nasdaq

trading. VeriSign rose $3.63, or 5.8%, to $66.25, and RSA Security gained $1.81, or 3.3%, to $57.50. Shares of Symantec were up $2.56, or 5.1%, to $52.88 and Entrust rose 50 cents, or 4.4%, to $11.75. Network Associates gained 28 cents, or 4.7%, to $6.32.