BOSTON, US: Symantec Corp, the world's top security software maker, will soon launch a Web-based storage service for consumers, joining a market led by EMC Corp's Mozy and privately held Carbonite.

Symantec Consumer Division President Janice Chaffin said in an interview on Monday that her company will start offering the new service at the end of next month.

"We think this is something that is going to be a big and growing opportunity," she told Reuters.

Symantec already offers 2 gigabytes of online storage for consumers as one of the offerings included with its Norton 360 suite of security software, which retails for about $80.

About 30 percent of its Norton 360 customers use the online backup feature. It runs in the background, automatically backing up important documents to Symantec's data center. They can easily be retrieved if a PC fails or files are accidentally deleted.

Symantec's new offering will be similar to that service, but will be sold a la carte, Chaffin said. She declined to discuss pricing or product features ahead of the launch.

The small but rapidly growing market is currently dominated by Mozy, which charges $5 a month for unlimited storage, and Carbonite, which sells unlimited storage for $50 per year.

Norton 360 users can store 2 gigabytes of data at no extra charge, but need to pay extra if they exceed that limit.

Chaffin said the new storage service is one of several in Symantec's pipeline of cloud computing products, or computer services that are delivered over the Web.

The company is also expanding into Web-based services that help secure PCs, improve their performance and allow users to remotely obtain technical support when their machines break down, she said.

Symantec's online storage services use technology that it acquired last year when it purchased privately held SwapDrive Inc for $124 million.

The business that Symantec built with the SwapDrive acquisition runs online storage systems behind the scenes for Internet providers and PC makers, which offer online storage products to their customers under their own brands.

Altogether, Symantec provides online backup for more than six times the number of consumer PCs as Mozy or Carbonite, Chaffin said.