Yahoo investors appear to be losing faith in Marissa Mayer's turnaround efforts

Yahoo Inc's shares fell 7.5 percent as the company's declining revenue tempered investor confidence in CEO Marissa Mayer's turnaround efforts, prompting several analysts to cut their price targets on the stock.

Yahoo's shares nearly doubled in the past year as investors pinned their hopes on Mayer and surging growth at Chinese online retailer Alibaba, in which Yahoo holds a big stake.

At least four brokerages lowered their price targets on Yahoo's stock, which fell to a low of $35.30 in early trading on Wednesday.

Yahoo on Tuesday reported a decline in online advertising prices and slower growth at Alibaba.

(Also see: Yahoo reports drop in revenue as prices of online ads slide)

Yahoo's overall revenue fell 6 percent in the last three months of the year to $1.266 billion, marking four consecutive quarters of eroding revenue.

The drop in revenue was largely driven by a 7 percent decline in ad unit pricing due to a shift to mobile, where ad rates were lower, and from the roll-out of a new ad format where volumes were strong but pricing was lower, SunTrust Robinson Humphrey analyst Robert Peck said.

Mayer, after taking take over in July 2012, moved aggressively to kick-start the company with product makeovers, acquisitions and big media hires. But the ad sales business continues to struggle when at a time rivals Google and Facebook are posting strong revenue growth.

Alibaba posted revenue growth of 51 percent during the July-September quarter, after setting a breakneck pace during the first two quarters of 2013.

"Alibaba remains the prime attraction, though its 3Q13 was perhaps a bit less robust than recent quarters," CRT Capital analyst Neil Doshi wrote in a research report.

The brokerage cut its price target on the stock to $47 from $52.

But Doshi said Alibaba's revenue growth could show signs of acceleration when Yahoo reports the Chinese company's fourth-quarter results. That period will include Singles Day (November 11), one of the biggest shopping days of the year in China.

Yahoo reports Alibaba's results one quarter in arrears as part of its own financial disclosures.

Analysts have estimated that Yahoo's Asian assets - Alibaba and Yahoo Japan - comprise about three-quarters of Yahoo's nearly $40 billion market valuation.

Some analysts raised their price targets on Yahoo's stock, citing the growth potential of Alibaba and another Yahoo asset, blogging service Tumblr.

"We think Tumblr may actually be capable of creating as much value as Yahoo's core (business)," Bernstein Research analyst Carlos Kirjner wrote in a note.

© Thomson Reuters 2014