Nearly a year and a half after the tragic death of Michael Jackson, the King of Pop continues to play a significant role in boosting the fortunes of his label Epic Records and its parent Sony Music Entertainment.

Jackson's total U.S. music sales are on pace to fall sharply in 2010 from last year, when grief over his untimely death on June 25, 2009, sparked a massive spike in sales of his catalog.

But Billboard estimates that Jackson's sales will still account for more than a fifth of Epic's overall recorded-music sales for 2010, helped by the highly anticipated December 14 release of "Michael" a collection of previously unreleased recordings.

Sony has been telling retailers that it expects "Michael" to generate U.S. sales in its first three weeks -- the final three weeks of 2010 -- that will top the first three weeks of sales for Jackson's 2009 hits collection "This Is It."

That seems like a tall order, considering that "This is It" was tied to the hit movie documentary of the same name and was released just four months after Jackson's death.

In addition, "Breaking News," the first song that Epic released from the album, drew a mixed reaction from radio programmers.

And notwithstanding Taylor Swift's remarkable million-plus, first-week sales for her album "Speak Now." the increasingly challenging sales environment for recorded music has contributed this year to disappointing debut weeks for albums from Katy Perry, Maroon 5, Kenny Chesney and the Zac Brown Band.

But given the timing of the release of "Michael," Sony's expectations don't appear to be overly optimistic.

"This Is It" came out on October 26, 2009, during the lowest sales volume week of 2009, according to Nielsen SoundScan. By contrast, the December 14 street date of "Michael" means its first two sales weeks will coincide with what are traditionally the biggest sales weeks of the year -- Christmas week and the week before Christmas.

Sony is expected to ship 900,000 units of the album and has told retailers that it expects "Michael" to debut with first-week U.S. sales of 400,000 units (15% of them digital), followed by sales of 280,000 and 84,000 in the each of the next two weeks.

That would top the debut-week sales of "This Is It" by 27,000. It would also give the new title a combined three-week tally of 764,000 -- 11% higher than the 686,000 units that "This Is It" sold in its first three weeks, according to SoundScan.

Another factor that will contribute to a strong debut for Michael" is the continued halo effect from Jackson's death.

In 2009, Jackson's U.S. album sales and sales of track-equivalent albums (or TEA, where 10 digital tracks equal an album) totaled 9.5 million units. This accounted for 7% of Sony's total sales in 2009 and 41.5% of Epic's sales, SoundScan says.

Those figures helped boost Sony's total U.S. market share in 2009 by more than two percentage points to 27.9%, from 25.2% in 2008, according to SoundScan.

So far this year through the week ended November 7, Jackson's album plus TEA sales totaled 1.8 million units, or 1.6% of Sony's sales and 12.7% of Epic's sales, according to SoundScan.

That's down sharply from last year, but already exceeds Jackson's full-year 2008 album plus TEA sales of 1.6 million, or 1.2% of Sony's sales and 11.9% of Epic's sales, SoundScan says.

Moreover, Billboard projects Jackson's sales through the rest of 2010, including sales of "Michael" to boost his full-year 2010 album with TEA sales to 3.2 million, accounting for an estimated 2.7% of Sony's full year sales and 22% of Epic's sales.