Amazon.com will launch a pay-per-view streaming movie service within weeks, founder and Chief Executive Jeff Bezos said Wednesday.

Speaking at the D: All Things Digital conference in Carlsbad, California, Mr. Bezos was quoted by Barron’s as saying that he is “very serious” about the music and video download business.

Mr. Bezos offered no details on the system, but said it would start instantly. Amazon already offers its Unbox video service, but that download service is not instantaneous and is limited to viewing on computers and via some TiVo digital video recorders.

On the news, shares of Amazon fell $1.01, or 1.3 percent, to $79.61 in afternoon trading.

Amazon’s announcement comes after Apple and Netflix disclosed their own new video releases.

Netflix earlier this month said it will let subscribers who pay at least $8.95 per month buy a $100 player by Roku that delivers videos to a television without waiting for a DVD to come in the mail.

In January, Apple Chief Executive Steve Jobs rolled out an update of the AppleTV set-top box that lets users choose movies and TV shows from their TVs without a computer hookup.

Amazon’s music download store also competes with Apple, whose iTunes store and iPod franchise dominate that end of the media download business.

Mr. Bezos, who was interviewed by The Wall Street Journal’s Walt Mossberg, also said Amazon was lowering the price of its Kindle e-book reader from $399 to $359. Kindle accounts for 6 percent of total sales of the 125,000 book titles available for the device, he said.