In the past,

Ventro

(VNTR) - Get Report

has had problems getting enough sellers to participate in the marketplaces it runs on the Internet. Now, it looks like the company is having problems finding buyers -- for itself.

Ventro shares spiked in early trading Monday after

Upside.com

reported that the firm had hired

Broadview

, a high-tech mergers and acquisitions firm, to solicit buyers for the company.

But then the shares started sinking. They finished regular trading down $2.06, or 15%, at $11.38. The stock's action suggests that investors don't believe a deal is imminent, something backed up by three analysts and one Silicon Valley executive.

"Other companies have indicated only a mild level of interest" in buying Ventro, says

Mark Gulley , a

Banc of America Securities

analyst. "I think they're really scratching now." (Gulley rates Ventro a buy because of its potential as an acquisition target, and his firm hasn't done underwriting for the company.)

A Ventro spokeswoman declined to comment. Broadview didn't return a call seeking comment.

For months, as the company's market cap has shriveled to about $500 million from an all-time high of $11 billion, speculation about Ventro's fate has swirled around Silicon Valley. Part of that speculation came after the company reported lower-than-expected transaction volumes last quarter. The company said that its customers were slower to integrate into its network than anticipated.

Analysts say the company has had technical problems along those lines, but that its close

relationship with major distributor

VWR Scientific Products

has discouraged suppliers from participating in Chemdex. Chemdex is Ventro's flagship exchange on the Internet, where it runs auctions and enables companies to buy and sell supplies in the life-sciences industry. Without enough suppliers, Ventro faces the classic chicken-and-egg conundrum of B2B, namely how do you get buyers before you've got enough sellers on your network, and vice versa.

Analysts say suppliers, instead, have chosen to list products on

SciQuest

( SQST), Ventro's main competitor. An ironic twist in all this is that SciQuest at one time was rumored to be on the block itself, with Ventro being named as the potential buyer.

"I know they've talked to SciQuest about a merger possibility," Gulley says. "The space is not that big to have two full-fledged players."

SciQuest decline to comment.

Gulley says he got that information from people at Ventro, but that the conversation took place some time ago. For now, fresh information on the company is hard to come by.

That's due, in part, to a chronic case of

stage fright on Ventro's part. The company has cancelled at least two presentations at investor conferences, as well as a day for analysts at the company. The fact that Broadview is reportedly making the rounds to find someone to take the company on could be why.

"At least it explains all the cancelled appearances," Gulley says. "That's the important thing."

For Ventro shareholders, finding a buyer is becoming increasingly important, as well.