Amazon.com is readying an updated Kindle Fire tablet, seeking to revive demand for the 10-month-old device as the market crowds with competing machines.

Amazon is holding an event today in Santa Monica, Calif., where it is likely to announce the newest versions of its line of Kindle e-readers and the Kindle Fire tablet, according to Anthony DiClemente, an analyst at Barclays.

The company said it sold out of the Kindle Fire last week.

The device’s first-quarter share of the market slipped to 4 percent from 17 percent the previous quarter.