James Best Jr./The New York Times

It is an unforgiving law of modern business: adapt or die.

Make that: adapt fast — or die even faster.

Like countless gee-whiz companies that captured and lost imaginations and dollars, BlackBerry, a giant of the pre-iPhone era, has faded with remarkable speed. After enduring years of dwindling sales, the company said on Monday that it was exploring “strategic options” — business code for searching for a savior.

For the moment, few seem to want to buy BlackBerry or, for that matter, its newest products. Unless a suitor emerges, BlackBerry risks joining the ranks of technology has-beens like Palm, Gateway and Commodore.

The abrupt decline of BlackBerry illustrates how consumers and investors demand almost instant change these days, especially from tech companies. And the window for redemption for a tech company that misses a step can be tiny indeed.

Four years ago, BlackBerry had 51 percent of the North American smartphone market, according to the research firm Gartner. And Mike Lazaridis, BlackBerry’s co-founder who was then its co-chief executive and co-chairman, was promising an even brighter future.

But then the company responded slowly to new iPhone and Android devices and the company’s sales evaporated. Now, the company has 3.4 percent of the market and Mr. Lazaridis is gone from BlackBerry.

BlackBerry’s board and its current chief executive, Thorsten Heins, portrayed Monday’s announcement as part of a new beginning, but few analysts and little of the tech community were buying that idea. Instead, BlackBerry is often grouped with other once-powerful tech companies, like Nokia and Dell, that are now struggling and appear to have hard roads back to growth, if any at all.

“Acquiring BlackBerry is necrophilia,” said Jean-Louis Gassée, a former Apple executive who was chairman of PalmSource, an unsuccessful attempt to turn Palm, once the leader in hand-held computing, into a software company. “The BB brand is tarnished.”

He added, in an e-mail typed on an Apple iPhone 5: “This former BB fan is sad.”

Exactly who would want to buy BlackBerry or how the company could finance going private was unclear on Monday. Speculation has circulated for years that large technology companies, notably Microsoft, have looked at BlackBerry and decided to pass. Smaller technology companies based in China undoubtedly covet BlackBerry’s brand and some of its technology, but the government of Canada, where the company is based, has strongly hinted that any such takeover would be banned on national security grounds.

If the company decides to go private, it would lose the distraction of having to manage quarterly financial results to protect the company’s share price. However, it is not obvious how the company could be transformed to restore growth and become attractive to new investors. BlackBerry has already significantly cut costs and reduced its work force. And whatever the merits or shortcomings of its products, they must compete against offerings from some of the largest and most profitable corporations in the world, including Apple, Google, Microsoft and Samsung.

While not everyone is as pessimistic as Mr. Gassée, there is little expectation that the move by BlackBerry would bring much wealth to the company’s beleaguered shareholders.

“We don’t foresee any scenarios where the value of the company will be significantly larger,” Tim Long, an analyst with BMO Capital Markets, a unit of the Bank of Montreal, wrote in a note to investors.

John Raoux/Associated Press

BlackBerry first announced that it was conducting a strategic review in 2012, after Mr. Lazaridis and its other co-chairman and co-chief executive, Jim Balsillie, stepped down in favor of Mr. Heins, a former Siemens executive who joined BlackBerry in 2007.

Their ouster followed a slump for the company as consumers moved to smartphones with full touchscreens, multiple cameras and hundreds of thousands of apps to choose from. BlackBerry’s devices largely stayed the same, often with half-screens and a physical keyboard.

But this year, the company introduced its largest and most ambitious turnaround effort so far, with its BlackBerry 10 line of phones. But it appears to have been too little, too late — the new devices have not dented Apple and Samsung’s grip on the market.

The failure of the BlackBerry 10 line of phones quickly led to speculation that BlackBerry, like Palm before it, would be broken apart and perhaps gradually disappear, at best lingering as little more than a brand name.

On Monday, however, BlackBerry’s directors did not specifically indicate why the company had now effectively decided on a major shake-up.

“Given the importance and strength of our technology, and the evolving industry and competitive landscape, we believe that now is the right time to explore strategic alternatives,” Timothy D. Dattels, the director who will lead the special committee overseeing the review, said in a statement.

When it was a small Canadian start-up company that pioneered wireless e-mail and then smartphones, BlackBerry repeatedly demonstrated innovation and defied forecasts that it would be outflanked or bought by competitors like Palm, Microsoft, Hewlett-Packard and Motorola.

As with many downfalls, the causes of BlackBerry’s descent are complex. But the arrival of the first iPhone in 2007 is somewhere near the center. In private conservations at the time, BlackBerry insiders and executives viewed the iPhone as more of an inferior entertainment device than a credible smartphone, particularly for users in BlackBerry’s base of government and corporate users.

BlackBerry had largely built its reputation on innovations in hardware, and by its standards, the early iPhone models were decidedly inferior. The iPhone fell well short of BlackBerry’s devices in areas like battery life and used far more data to do their jobs, partly because they lacked BlackBerry’s unique global network.

The company’s roots may also have blinded it to how Apple had made software, not hardware, the defining feature of smartphones. For much of BlackBerry’s history, the company actively and openly designed phones that primarily pleased corporate and government information technology departments. Corporate security concerns meant, for example, that BlackBerrys were among the last cellphones to include cameras.

But the iPhone’s arrival, and Google’s subsequent purchase of Android, coincided with more companies requiring employees to buy their own phones. Rather than immediately developing a new operating system to compete with Apple and Android, the company tried to adapt its existing software. The resulting phones, the Torch and the Storm, were widely seen as technology and market failures.

“The world did not stop for BlackBerry, and we’re seeing the result of that today,” said Bill Kreher, an analyst with Edward Jones.

When Mr. Lazaridis and Mr. Balsillie did finally commit the company to developing what became BlackBerry 10, the project was repeatedly delayed. While the new phones and operating system proved more incremental than innovative, their main problem, many analysts say, was that the new devices arrived too late.

“BlackBerry’s situation would not be really as dire if BlackBerry 10 had come out two years ago,” said Charles Golvin, a technology analyst at Forrester Research. “The question now is whether all these things that make up BlackBerry still make sense as a single company.”

Michael J. de la Merced contributed reporting.