Adobe said on Tuesday that it has reached a deal to acquire Web analytics firm Omniture for $1.8 billion, or $21.50 per share.

That represents a 45 percent premium to Omniture's average closing price for the last 30 days, Adobe noted in its press release. Omniture, which was started in 1996, has about 1,200 employees and took in just under $300 million in the 12 months ending Dec. 31.

Adobe CEO Shantanu Narayen called the move a "game changer" for the company.

"Adobe customers are looking to us for solutions to deliver engaging experiences and more effectively monetize their content and applications online," Narayen said in the press release announcing the deal.

The two companies said the deal is expected to close during Adobe's fourth quarter and is subject to government approvals. Omniture will become a new unit within Adobe, with Omniture CEO Josh James continuing to lead the business as an Adobe senior vice president. Adobe said the deal should add to earnings in fiscal 2010.