NEW YORK, JULY 17 -- The Dow Jones industrial average closed unchanged yesterday, failing for the third consecutive session to close above the 3000 mark.

The precisely flat close capped a session dominated by both earnings-inspired and program-driven whipsaws, with trading bouncing within a 31 point range.

The market was buoyant in early trading on bullish earnings reports by such companies as Coca-Cola, Wells Fargo and Honeywell, but was ultimately undermined by mounting losses in United Telecom, which posted earnings well below expectations. The company's stock plunged as much as 23 percent on over 11 million shares, but it wasn't the only issue suffering a price collapse.

Lowe's Cos., the consumer-goods and building materials specialist, plummeted to a 13 percent loss at session lows, apparently for no other reason than a report by Oppenheimer & Co. analyst Bruce M. Missett sharply reduced earnings projections and dropped Lowe's from the firm's recommended list.

The Dow translated its midmorning, 11-point gain to a modest, 8-point loss by midafternoon, but computerized buy programs turned the blue chips on a dime in the last hour, sending the index reeling back to where it began the day by the closing bell.

At the close, the Dow stood at 2999.75, unchanged despite moderately wide swings that created highs near 3011. Declines outpaced advances for most of the day, and by the close outpaced gainers on the Big Board by about 4 to 3.

New York Stock Exchange volume was active at 176 million shares, but 6 percent of this volume was accounted for by United Telecom. Another 4.5 percent was in Chase Manhattan and GTE Corp., which traded heavily after earnings reports.

''At today's highs, the Dow was up over 100 points in just six and a half sessions, and there's got to be some healthy profit-taking going on here,'' said chief trader Thomas Callahan at Yamaichi International. ''What's more, you've got a lot of people who have been buying the same stocks at Dow 3000 that they were buying at 2500, except they're buying them at 18 times earnings instead of 14 times earnings.''

At some point, investors are temporarily satiated, and they tone down purchases in hopes of an advantageous entry point following a normal pullback, Callahan said.

The Dow transports closed down 2.02 at 1187.59, while the utilities eased 0.75 to 205.11.

The Standard & Poor's 500 was down 1.43 at 367.52, the NYSE Composite was down 0.64 at 200.49, the Value Line lost 1.34 at 289.59, the Amex Market Value decreased 1.19 at 364.39 and the Nasdaq Composite fell a hefty 5.12 at 464.48 as risk-averse investors scrambled out of those secondary stocks for which earnings appear uncertain.