(Adding replacements for Orenberg and Grebennikov)
BOSTON, May 2 (Reuters) - At least five senior executives have left Russian computer security software company Kaspersky Lab in the past month due to a disagreement over the way it is being run under its chief executive and co-founder, Eugene Kaspersky.
The executives include the company's North American president, Steve Orenberg, who is credited with making Kaspersky a major anti-virus brand in the United States, and its chief technology officer, Nikolay Grebennikov, who headed global research and development.
Eugene Kaspersky, in an emailed statement, praised Orenberg and his team for helping shape the success of the anti-virus software maker in the United States, saying they "made the impossible possible." However he added that "in evaluating our business and in creating a plan to move forward in the U.S., we had a disagreement about business strategy."
Kaspersky did not respond to requests this week via email for more detailed comment on the departures.
Company spokesman Alejandro Arango told Reuters via email that Orenberg and Grebennikov left by mutual agreement with the company. He, too, declined to elaborate on their differences.
It is the second major management shift at the privately-held company since 2011 when Eugene Buyakin, the chief operating officer, resigned. At about the same time, the company's co-founder, chairwoman and former CEO, Natalya Kaspersky, who is also Eugene Kaspersky's ex-wife, sold her remaining shares in the company.
Buyakin and Natalya Kaspersky told Reuters in 2012 that they severed ties with the Moscow-based company partly over disappointment that Eugene Kaspersky had decided to abandon plans to take the company public. Eugene Kaspersky controls a majority of the stock in Kaspersky Lab. ( http://reut.rs/1uej38W )
In a telephone interview, Orenberg declined to explain what the dispute that led to his departure was about.
"There was a difference of opinion. We basically very politely agreed to disagree on what we needed to do," he said. "It made sense for me to make an exit and the company needed to do what it needed to do."
Orenberg joined Kaspersky 10 years ago. He launched the brand in the United States, convincing retailers like Best Buy to promote the once unknown Russian name over well-known products like Symantec Corp's Norton anti-virus software and McAfee, which is now owned by Intel Corp.
Grebennikov could not be reached for comment. He joined the company in 2003 as a systems analyst, was quickly promoted to head development of its flagship anti-virus software and later all of research and development.
"Nikolay led the department for five years and in that time it has turned into a large industrial development organization. I would like to sincerely thank Nikolay for the work he has done," Eugene Kaspersky said in his statement to Reuters.
The company appointed its senior vice president for corporate sales in North America, Chris Doggett, to the position of managing director for the region, saying he will be responsible for sales, marketing and business development.
It also named its deputy CTO, Nikita Shvetsov, as acting CTO.
Other executives who recently left the company include Petr Merkulov, the Massachusetts-based North American executive vice president, and John Malatesta, the Milan-based global head of corporate marketing. They could not be reached for comment.
The company's U.S.-based vice president of government and strategic relations, Timur Tsoriev, also left last month. He declined comment.
The company's revenue last year rose 6 percent to $667 million, according to unaudited results, Arango said.
That was faster than the 3 percent revenue growth posted in 2012, though slower than the double- and triple-digit percentage growth of prior years as the company climbed from obscurity to one of the world's biggest makers of anti-virus software.
Kaspersky was the No. 4 maker of anti-virus software in 2012, behind Symantec, McAfee and Japan's Trend Micro Inc , according to market research firm IDC. Data for 2013 is not yet available.
(Reporting by Jim Finkle; Additional reporting by Alina Selyukh in Washington; Editing by Richard Valdmanis, Leslie Adler and Paul Simao)