Mid-cap software firm California Software (Calsoft) has announced the acquisition of 51% equity stake in US-based Informed Decisions Corp (IDC) for $2 million, making this its fourth acquisition in the last 12 months.Calsoft would acquire majority stake in $7 million turnover IDC through its fully-owned US subsidiary CSWL, top officials of Calsoft and IDC said in a joint statement.The acquisition, which is subject to necessary approvals, would be completed by the end of this current quarter, Sam Santhosh, MD and CEO of Calsoft said. The company would pay $1 million upfront while the remaining amount would be invested in IDC over a period of three years, as per the deal.IDC, which focuses on education products for universities and higher learning institutions in the US, enable its clients (over 65 institutions) to manage the payment and collection process from over a million enrolledstudents."This relationship opens new vistas in addressing the growing higher education market not only in North America, but also globally through our international offices," Sam said.This is the fourth acquisition by Calsoft, after it acquired 51% stake in Kochi-based Team Frontline in September 2004 and 100% stake in Bangalore-based Web Spectrum Software in December 2004. In March 2005, Calsoft acquired US-based healthcare software firm AmericanHealthnet.Santhosh said the four acquisitions cost Calsoft less than $5 million.