In short - Yes, it's true, and he did it for the money.
In 1984 a company named ATV, who controlled the publishing rights of about 4,000 song (including most of The Beatles' songs) put its catalog for sale. Jackson offered 47.5 million dollars, and being the highest bidder (out-bidding Paul McCartney, among others) got the publishing rights (not including some of George Harrison's songs and 4 Lennon-McCartney songs from the very early Beatles era). The result is that 50% of all royalties from The Beatles' songs are Jackson's (the remaining 50% goes to McCartney and to John Lennon's estate).
Later on, Jackson's ATV catalog was merged with the Sony corp. music catalog, and now the ownership is 50% Jackson's and 50% Sony's. There were speculations that Jackson will have to sell his share to get himself out of financial troubles, but that didn't happen so far.
You can find more here and here.