Apple Inc. is preparing to launch a tablet personal computer in late March or April, with manufacturer partners poised to roll out as many as 1 million units per month, according to an Oppenheimer research note.

The highly anticipated tablet is expected to pitch Apple into the digital book market popularized by Amazon.com's Kindle e-reader. Apple declined to comment.

Oppenheimer analyst Yair Reiner said the new tablet could boost Apple's earnings per share by 25 cents to 38 cents per quarter, assuming that it sells 1 million to 1.5 million units each quarter at an average price of $1,000 and a corporate average net income margin of 22 percent.

"Our checks into Apple's supply chain indicate that the manufacturing cogs for the tablet are creaking into action and should begin to hit a mass market stride in February," Reiner wrote.

"The February ramp schedule suggests a late March or April commercial release, since Apple will need to build at least 5-6 weeks of inventory before going live."

He said the tablet will have a 10.1-inch multitouch LCD screen similar to that of Apple's iPhone.

Apple has also approached book publishers to distribute their content electronically, and has offered them a revenue cut of 70 percent without requiring exclusivity, Reiner said.

He said that compares favorably to the Kindle's 50 percent deal, and that Kindle only offers a 70 percent cut to publishers that give Amazon exclusive rights.

"As innovative as it is, we believe the Kindle has disgruntled the publishing industry (book, newspaper, and magazine) by demanding exclusivity, disallowing advertising, and demanding a wolfish cut of revenue," Reiner wrote. "The tablet is set to change that."

Reiner forecast Apple's fiscal 2010 profit at $8.39 per share, compared with $6.29 in fiscal 2009, saying his estimate has not yet factored in the new device.

Shares of Apple were up 1.6 percent at $192.89 on Nasdaq.