eBay (EBAY) - Get Report may be hurting for a new growth opportunity, but Skype won't kill the pain, say analysts.

Reports that the online auction giant is in talks over

a multibillion-dollar deal with Net-calling upstart Skype sent eBay's shares down 3% Thursday as Wall Street gave a thumbs-down on the possible pairing.

"If eBay was considering whether to make this move, it would be a not-so-subtle admission that growth is slowing," says Hoefer & Arnett analyst Marty Pyykkonen, who has a reduce rating on eBay.

After a decade of rapid growth, eBay has stagnated. Now, with a $2 billion pile of cash and short-term investments, the San Jose Net auctioneer seems to be looking for some new direction.

While both eBay and Skype are Internet businesses, there are few other similarities, say analysts. eBay pioneered and now dominates a virtual marketplace connecting buyers and sellers. Skype created communications software and a system of connecting PC users with a free calling service.

Skype promises to do with voice-over-Internet protocol, or VoIP, what creators Niklas Zennstrom and Janus Friis did for music with file-sharing service

KaZaA

.

Analysts say they were encouraged to hear that eBay may be addressing its sluggish sales, but some were alarmed to hear the company was considering an entirely new business path.

"When I heard about it, I was wishing it was a rumor, for the sake of eBay," says ABI Research analyst Vamsi Sistla. "Skype is too far of a stretch. If they really want to grow, there is more lower-hanging fruit out there."

Skype's success quickly captured the tech industry's imagination. And suddenly it looked like VoIP was poised to upend the old-line telcos. But speculated deals with Internet titans like

Yahoo!

(YHOO)

and

Google

(GOOG) - Get Report

haven't materialized, as both outfits opted to buy smaller players or develop their own VoIP services.

"VoIP is hot, I'll agree, and cheap to build, but the revenue is tiny," says Sistla.

Offering eBay users a calling service could foster better communications between buyers and sellers, but there doesn't seem to be anything that could be considered more compelling to a Skype strategy, say analysts.

"I would find it hard to believe anything they'd say about synergistic advantages," says Pyykkonen.

ABI's Sistla summed up the eBay/Skype idea in a metaphor.

"I can understand a cheetah trying to be a tiger, but this is much different," says Sistla. "It's more like a cheetah trying to be an elephant."