Adobe has agreed to buy Web analytics company Omniture for $US1.8 billion in cash, the companies said Tuesday.

The price San Jose, California-based Adobe is paying for the company, which is $US21.50 per share, is at a 45 percent premium over Omniture's average closing price for the last 30 trading days, Adobe said.

Adobe, known for multimedia design, Web-development and document-creation software such as Flash, Dreamweaver and Acrobat, said the purchase will help the company add Web analytics and optimization capabilities directly to those products.

For designers, developers and online marketers using its tools, this new capability will help them streamline how they create and deliver relevant content and applications, Adobe said. Advertisers, advertising agencies, publishers and online retailers can improve the experience of their end users and get more out of their digital media through the new analytical capability, the company said.

Following the close of the deal, Omniture will become a new unit within Adobe, the company said. Omniture's CEO Josh James will join Adobe as senior vice president in charge of that business unit, reporting to Adobe President and CEO Shantanu Narayen.

The companies expect the deal to close in the fourth quarter of Adobe's fiscal year, which ends Nov. 27.

Adobe and Omniture are scheduled to hold a conference call about the deal Tuesday afternoon.

(More to follow.)