The

Dow Jones Industrial Average's

first embrace of 10,000 proved just a fleeting flirtation, as the blue-chip index (along with much of the rest of the market) quickly retreated into the red.

The Dow lately was down 4 to 9955, having peaked at 10,001.79 around 9:50 a.m. EST. Strength in

Union Carbide

(UK)

and

Merck

(MRK) - Get Report

helped to power the milestone-cracking move, but those stocks were off their best levels and most Dow components were down. The

S&P 500

was down 1 to 1306.

The tech-spiced

Nasdaq Composite Index

was holding onto positive ground with its fingernails, up 4 to 2435 behind solid trading in

Intel

(INTC) - Get Report

and

Applied Materials

(AMAT) - Get Report

. Small-caps weren't so lucky, with the

Russell 2000

down fractionally at 400.

TheStreet.com Internet Sector

index was up 5 to 610 and

TheStreet.com E-Commerce Index

was up a strong 3 to 113. E-Commerce Index component

Cyberian Outpost

(COOL)

was soaring 6 15/16, or 37%, to 25 7/16 on the launch of its new online computer auction site.

Market breadth was negative on both major exchanges.

New York Stock Exchange

decliners were outpacing advancers 1,412 to 1,110 on 213 million shares. On the

Nasdaq Stock Market

, 1,741 losers were leading 1,394 winners on 294 million shares.

New 52-week highs were ahead of new lows by 37 to 33 on the NYSE and by 52 to 46 on the Nasdaq.

Most active on the NYSE was

America Online

(AOL)

, up 2 7/8 to 104 13/16 on 9 million shares.

The Nasdaq's most active issue was

eFax

(EFAX) - Get Report

, up 8 7/8, or 41%, to 30 3/8 on 13 million shares. eFax was up after inking a pact to provide free fax-to-email service to

Xoom.com

(XMCM)

members. Xoom was down 4 11/16, or 7%, to 66 1/2.

9:50 a.m.: Dow Inches Toward 10,000

Stocks inched higher in the early going, as the

Dow Jones Industrial Average

gained 21 to 9980, crawling ever closer to the 10,000 level.

The Dow got a boost when component

Union Carbide

(UK)

began trading. It was up 2 1/2, or 6%, to 46. Union Carbide this morning said first-quarter operating earnings should come in within a few cents of the highest-published

First Call

analyst estimate, which is 47 cents. The current 10-analyst consensus estimate has Union Carbide earning 34 cents a share in the first quarter.

Elsewhere, the

S&P 500

was up 3 to 1310.

The

Nasdaq Composite Index

was up 5 to 2436. The

Russell 2000

was up 1 to 402.

TheStreet.com Internet Sector

was up 10 to 615.

TheStreet.com E-Commerce Index

was up 5 to 115.

The 30-year Treasury bond was up 4/32 to 96 5/32, yielding 5.51%.

Most Up at Open -- NYSE

Teradyne (TER) - Get Report, up 2 9/16 to 54

.

Most Up at Open -- Nasdaq

Go2Net (GNET) , up 14 5/8 to 128

: Paul Allen, co-founder of

Microsoft

(MSFT) - Get Report

, said yesterday he would invest up to $750 million in Go2Net for a controlling stake in the company.

Most Down at Open -- NYSE

Procter & Gamble (PG) - Get Report, down 1 3/16 to 90 1/2

.

Most Down at Open -- Nasdaq

Xoom.com (XMCM) , down 2 5/8 to 67

: The company filed with the

Securities and Exchange Commission

for an offering of 4 million common shares.