San Francisco investment firm buying American Pacific Corp.

American Pacific Corp., a chemical company based in Las Vegas, on Friday accepted a $392 million takeover bid from the Miami investment firm H.I.G. Capital.

Terms call for H.I.G. launching an offer within two weeks to buy all the shares at $46.50 a share, an 18.9 percent premium over Thursday’s closing price of $39.12 and more than quadruple the price just 14 months ago. In the wake of the announcement, the stock closed Friday at $46.48.

The company has maintained a relatively low local profile, with only a 22,500-square-foot executive office at the HC|Hughes Center and a small groundwater remediation site in Henderson. Its plants are located in Texas, California and Utah.

Neither American Pacific nor H.I.G executives could be reached for comment on how the deal might change the company. According to the annual financial statement filed with the Securities and Exchange Commission, the employee count stood at 530 as of Sept. 30, but did not detail how many were local.

However, the company’s place in local history stems from its ownership of the PEPCON subsidiary that manufactured a white powder called ammonium perchlorate, a key ingredient to boost the potency of solid rocket fuel. It gave the company its start in 1955.

The PEPCON plant in Henderson suffered a series of three massive explosions on May 4, 1988, that killed two people and injured 372 with a force that could be felt on the Strip and was reported to buffet a plane on approach to McCarran International Airport. A Sandia National Laboratories report estimated the peak power of the explosions at one kiloton, the size of a small nuclear weapon.

The plant was closed for good the next year and production shifted to Cedar City, Utah, where the company established a buffer zone. Although a company subsidiary retains the PEPCON name, which originally stood for Pacific Engineering and Production Company of Nevada, the ammonium perchlorate factory now falls under the Western Electrochemical Co. banner.

The Henderson facility is designed to remove ammonium perchlorate from the groundwater and was upgraded and enlarged in October with a new filtration system based on a technology called a fluidized bed reactor. The site is near the junction of U.S. Highway 95 and the 215 Beltway.

Almost all of American Pacific’s $215.1 million in revenues last year came from manufacturing two types of chemicals. One group, called fine chemicals, form the active ingredients in drugs to treat cancer, viral infections and central nervous system disorders.

The other category, specialty chemicals, is dominated by ammonium perchlorate. Company financial statements describe this as generating steady sales, but fat operating margins that ran 58 percent last year compared to just 9 percent for fine chemicals. This came even though fine chemical sales ran $124.9 million compared to $82.6 million for specialty chemicals.

Income from on-going operations of $23.1 million marked a 13.8 percent gain from 2012. Some of that, CEO Joseph Carleone said during a conference call in December, resulted from an unusual surge in ammonium perchlorate demand that would not repeat this year. The return to profits in 2012 came after three straight years of losses starting in 2009.

For more than a decade, the stock seldom traded higher than $10 a share and dipped as low as $4.42 in September 2010. But the rebound began with the improving financial results and accelerated after an investors conference last March when top executives said a review of “strategic alternatives” had begun. Frequently, in Wall Street speak, the means a company will sell part or all of itself.

As published rumors last year talked of an impending deal, the stock soared as high as $60.36 in October. When asked about it by an analyst in December, Carleone responded, “When we see undocumented reports that come from unknown and unidentified sources, it becomes very hard to give anyone who is willing to report in that irresponsible madder any credence whatsoever.”

H.I.G says it has more than 50 companies in its current portfolio and at some point has invested in or managed more than 200.

Contact reporter Tim O’Reiley at toreiley@reviewjournal.com or at 70-387-5290.