Faced with problems in its rocket and satellite business, as well as cost overruns on two high-profile Pentagon aircraft programs, Lockheed Martin Corp. may soon warn Wall Street that second-quarter earnings will be below estimates.

A Lockheed spokesman would not confirm what defense industry watchers and the investment community predict is likely: a downward revision of the consensus earnings estimate of leading Wall Street brokerages, now pegged at 72 cents, according to First Call.

Lockheed has said for some time that it would update its quarterly and year-end profit forecasts in advance of the release of second-quarter earnings during the third week of July. Industry sources said the announcement will likely come soon, perhaps before next week's Paris Air Show, where aerospace companies typically meet with analysts.

The consensus estimate already has fallen 10 percent since mid-April, when the Bethesda-based company began experiencing failures with its popular Titan rocket. The estimate fell 2 cents last week after Morgan Stanley Dean Witter analyst Pierre Chao lowered his estimate, which had been on the high end of the group, to 65 cents a share from 85 cents.

"It doesn't surprise me," said Robert Friedman, an analyst with Standard & Poor's Equity Group. "I think I have the only `avoid' rating on the street."

Friedman said he thinks Lockheed has the wrong mix of businesses to outperform the S&P 500 index, which is a broad measure of the overall stock market. He also expressed concerns about what he termed Lockheed's "uninspired management."

Lockheed stock has lost nearly 30 percent of its value since reaching a 52-week high of $56.75 in late October. Shares of Lockheed closed yesterday at $40.43 3/4, down $1.06 1/4, on the New York Stock Exchange.

For almost a year now, Lockheed has been rocked by a series of mishaps -- some of them self-imposed -- that have bedeviled the country's largest defense contractor. In November, chief executive Vance Coffman surprised investors when he told them the company's 1998 earnings would not match the estimates of analysts. The company's first-quarter earnings were down 30 percent from a year earlier.

Lockheed's troubles began last spring when the government announced its opposition to the company's $12 billion deal to acquire rival Northrop Grumman Corp. The Justice Department later sued Lockheed to block the purchase, which it deemed anti-competitive, and Lockheed abandoned the deal in July.

In August, a Titan rocket blew up along with its $1 billion classified military satellite. The program subsequently was suspended pending a review, but problems recurred in April with two successive launch failures. Lockheed has acknowledged that one of those losses will cost the company $40 million in potential bonuses the Air Force pays for successful launches. That is in addition to $29 million in lost fees from the August failure.

The company has not indicated whether it will suffer penalties from an April 9 launch failure, which is believed to have originated with an upper-stage power unit made by Boeing Co., or from an April 27 launch failure for a private company trying to market satellite images to commercial users.

These problems and the failure of a Lockheed anti-missile weapon to hit its target despite repeated tests led the company last month to establish an independent panel to review its space and missile business. That review is scheduled to be completed by September.

The company has more earthbound problems as well. Last week Lockheed said it would lay off 2,000 workers at its Marietta, Ga., factory, more than 20 percent of the work force there. The plant produces the C130J cargo plane and the F-22 supersonic fighter, both of which are suffering cost overruns.

Also over budget is the new Joint Strike Fighter, on which Lockheed's military aircraft business is pinning its future. The JSF program is reported by industry journals to be $100 million over its $700 million development budget.