Google

(GOOG) - Get Report

may be adding digital music to its ever-increasing array of services, according to a Wall Street analyst.

A beta or test of the service will be rolled out in the next three to six months, says Bear Stearns analyst Robert Peck, who rates the shares of the Mountain View, Calif.-based company outperform. Bear has provided non-investment banking service for Google and makes a market in the stock.

The service is a logical outgrowth of Google's strategy to create an array of services that complement its search business. Earlier this month, the company unveiled a video store that allows people to download some television shows.

"We do think this fits with Google's recent moves and its ultimate goal of organizing the world's information," Peck writes in a note to clients, noting that Google hasn't confirmed his theory. A company official couldn't immediately be reached for comment.

Google's success at digital music is far from a sure thing. The company's video store was panned, prompting the company to admit that it had erred in how it designed its service. Other features that Google has developed including its Froogle comparison shopping site haven't proven to be popular with the public.

Apple

(AAPL) - Get Report

, which has sold 850 million songs through iTunes, is a juggernaut in the digital music bus. That gives it 83% of the U.S. market, according to Nielsen SoundScan's December numbers.

Other companies including

Microsoft

(MSFT) - Get Report

,

Yahoo!

(YHOO)

and

Real Networks

( RWNK) haven't been able to make a dent in Apple's commanding market share.

"They are playing second and third fiddle to Apple,'' says Tim Bajarin, the president of Creative Solutions, a market research and consulting firm based in San Jose, Calif. "It's going to be hard for Google to compete with Apple."

Google may find a sympathetic ear among the recorded music industry, which has loudly complained about Apple's insistence on charging 99 cents for each download. The protests haven't spurred the Cupertino, Calif.-based company to change its position.

Shares of Google, the No. 1 search engine, fell $2.87 to $431.30 during trading Friday. The company is due to report earnings Jan. 31. Apple fell 62 cents to $71.71.

Senior writer Troy Wolverton contributed to this report.