RealNetworks ( RNWK) turned a year-ago loss into a profit in the third quarter, thanks in part to a 20% jump in revenue and the sale of an equity investment.

The company's results topped Wall Street's expectations, but the company warned that fourth-quarter results may fall a little shy of them.

Investors jeered the news. In recent after-hours trading, the company's stock was off 41 cents, or 5%, to $8.28.

The company, which makes software that encodes and plays digital music and movies, earned $11.2 million, or 6 cents a share, in the just-completed quarter, on $82.2 million in sales. In the third quarter last year, Real lost $7 million, or 4 cents a share, on $68.3 million in sales.

Included in the company's results this quarter was a gain of $8.4 million, or 4 cents a share, on an expected sale of an investment in a Japanese company.

Including that windfall, but excluding costs related to its recently settled antitrust suit against Microsoft ( MSFT), Real would have earned $14.7 million, or 8 cents a share.

Analysts were looking for earnings of 4 cents a share on $82.2 million in sales, according to a poll by Thomson First Call. The company in August predicted it would earn 4 cents to 5 cents a share -- or 6 to 7 cents excluding litigation costs -- on revenue of $80 million to $82 million.

For the fourth quarter, Real expects to earn $1.42 to $1.48 a share on sales ranging from $81 million to $85 million. The midpoints of that guidance are earnings of $1.45 a share on $83 million in sales.

That's somewhat below Wall Street's estimates. The Street had predicted a profit of $1.48 a share in the holiday quarter on sales of $87.91 million.

Shares of Real ended the regular session up 22 cents, or about 3%, to $8.28.