HarperCollins Publishers, struggling with how to fit e-books into its U.S. sales strategies, says it has delayed the electronic release of Sarah Palin's memoir.

The publisher had originally intended to release the former Alaska governor's memoir, "Going Rogue: An American Life," in e-book form on Nov. 17, the same date as the hardcover edition's release. But Tuesday HarperCollins said it would push the e-book release date back to Dec. 26 to give the hardcover version more time to register sales, The Wall Street Journal reported.

Palin's book had been intended for a spring release, but HarperCollins indicated it would have 1.5 million copies of the former Republican vice-presidential candidate's book ready in November. It was the second time this month a publisher decided to delay the e-book version of a popular title. The electronic edition of the late Sen. Edward Kennedy's memoir, "True Compass," has also been delayed.

"This is the first time we're trying this, and we'll see what we learn," HarperCollins chief executive Brian Murray told the Journal. "The publishing plan is focused on maximizing velocity of the hardcover before Christmas, at a time when hardcover sales in the industry are down 15 percent."