Amazon.com on Friday sent out enigmatic invitations to a press event, fueling expectations that the online retail titan will release a tablet computer to challenge Apple's iPad.

Invites to the Wednesday press conference in New York City offered no clue to what Amazon had in store.

Amazon has not publicly announced plans to produce a tablet but numerous press reports have said the online retail giant will come out with one this year.

Technology research firm Forrester predicts that an Amazon device could be the first legitimate challenger to Apple's iPad.

Amazon's "willingness to sell hardware at a loss combined with the strength of its brand, content, cloud infrastructure, and commerce assets makes it the only credible iPad competitor in the market," according to Forrester analyst Sarah Rotman Epps.

The Seattle, Washington-based Amazon, maker of the Kindle electronic book reader, is capable of "disrupting not only Apple's product strategy but other tablet manufacturers' as well," she contended in a recent blog post.

Apple sold 9.25 million iPads last quarter and dominates the market for the multi-media devices, which are also being produced by South Korea's Samsung, Blackberry maker Research In Motion and scores of other companies.

But none of the iPad's rivals has managed to put a scare so far into the California-based gadget-maker whose legendary co-founder Steve Jobs stepped down as chief executive last month.

According to technology research firm Gartner, the iPad will account for 68.7 percent of the 69.7 million tablets to be sold this year and will remain the top-selling device over the next few years.