Thermo Instrument Systems Inc. of Waltham, Mass., has completed the acquisition of 98 percent of all outstanding shares of Spectra-Physics AB, based in Stockholm, Sweden, according to documents filed with the US Securities and Exchange Commission. This gives Thermo an 80.4 percent stake in Spectra-Physics Lasers Inc. in Mountain View, Calif. Earl Lewis, CEO of Thermo Instrument, said the strategy for acquiring more shares of Spectra-Physics Lasers depends on how the company's stocks perform: "If we think it has good potential for growth, we'll keep it public. If not, we'll buy [the shares] back." Lewis said he expects to examine each of the markets, applications and technologies that Spectra-Physics Lasers is involved in before making any business decisions. "This will be a 'get to know each other' period," he said. "We're not rocking the boat. The worst thing is to shake things up. We'll go slow and steady, and understand the business first before making changes." He added that he expects no change in management.