After riding out two technology boom-and-bust cycles, Savvis' major shareholder apparently doesn't want to let a third opportunity pass it by.

The data-center and cloud-computing firm agreed Wednesday to be bought for $2.5 billion by CenturyLink of Monroe, La., capping three months of rumor and speculation that sent Savvis' stock price up by nearly 50 percent.

CenturyLink's $40-a-share offer was enough to win over Welsh Carson Anderson & Stowe, a New York private equity firm that controls 18 percent of Savvis' shares. Welsh Carson has been a patient investor for a dozen years, but one analyst believes it started eyeing the exits in early 2010.

"We've thought they were trying to dress up the company and shop it around for the past year," said Donna Jaegers, a Denver-based telecommunications analyst for D.A. Davidson & Co.

To her, the first signal came in March 2010, when Savvis announced that longtime director Jim Ousley would be its new chief executive. Ousley, 65, had led two other technology companies into acquisitions: Control Data Corp. in 1999 and Vytek Wireless in 2004.

"When you've done a management search and you end up with someone in their mid-60s, that says something," Jaegers said. Ousley did a great job of strengthening the company, she added, as reflected by a stock price that was rising even before takeover speculation heated up in late January.

That's when Verizon agreed to buy Terremark Worldwide, a direct competitor of Savvis, for $1.4 billion. Analysts immediately pointed to Savvis as the next likely takeover target.

Clayton Moran, an analyst at Benchmark Co. in Boca Raton, Fla., put a $40 price target on Savvis immediately after the Terremark deal. That prediction was spot-on, but he now believes Savvis could have held out for more.

"We believe there is a potential for a competing bid or sweetener," Moran wrote in a report issued Wednesday. In a telephone interview, he said Savvis also could have continued to thrive on its own.

"As an independent company, they had very good momentum," he said. "From a shareholder perspective, you can argue that the stock would have gone above $40 just based on performance."

Ousley told analysts that Savvis had shopped for other offers before accepting the CenturyLink bid, and couldn't find a better one.

From Welsh Carson's perspective, $40 apparently was good enough. The private-equity firm bought Savvis in 1999 and combined it with a network owned by Bridge, a financial-information firm that later went bankrupt. It took Savvis public in 2000 at a price that's equivalent to $360 a share today, and then watched the shares lose 99 percent of their value when the dot-com bubble collapsed.

After Welsh Carson pumped more money into Savvis, the stock recovered to more than $50 by April 2007. Savvis was the subject of takeover rumors then, too. Then the recession hit, followed by a financial crisis, and Savvis shares fell as low as $5.09 in early 2009.

Private-equity firms usually like to cash out investments in a decade or less, so Welsh Carson probably was getting a bit impatient. With the technology and stock-market roller-coasters turning upward again, this had to look like an opportunity not to be missed.

On Sunday, we'll look at what the acquisition by CenturyLink might mean for the St. Louis area.