The ESC had been hunting for a foreign investor this summer and is happy to sign the deal with Securitas, a company active in the security, cash-in-transit and alarm business.
The ESC will increase its share capital to 14 million kroons ($1 million). The company announced it plans to have a turnover of 60 million kroons by increasing its market share to 20 percent.
The ESC together with Securitas Eesti, the Estonian subsidiary, presently controls 10 percent of the market.
"I see two big security companies in Estonia in the future, ESS and Securitas," said Bjorn Brisere, Securitas manager for the East European market.
ESS, after the merger with Eesti Valvekoondise, now controls 60 percent of the market. The second largest company is Akropol, which controls 10 percent of the market.
The ESC previously held about 8 percent, while Securitas controlled 3 percent of the market. The total turnover of the Estonian security service market is about 600 million kroons.
"Together we can cover 75 percent of the country with our services," said Brisere. The new entity has a staff of about 450 people and about 1,000 clients.
The ESC was established in 1991 and is one of the oldest security companies in Estonia. Together with other security companies, the ESC started an Estonian Security Companies Union in Estonia, which celebrates its fifth anniversary this year.
William Cronenberg, a member of the American Society for Industrial Security, said the Estonian security market has developed quickly over the past five years. The Latvian market, he noted, is at least five years behind its northern Baltic neighbor.
"The Estonian security system is something opposite to the American system," Cronenberg said. "Here, security officers drive around and sometimes exercise police functions. It is good if we can use the services through private companies if police are unable to do it."