(Reuters) - Shares of Amazon.com Inc (>> Amazon.com, Inc.) were set to jump about 7 percent at the opening on Friday after the company reported better-than-expected sales growth in North America and indicated strong momentum going into the U.S. holiday season.

At least 15 brokerages raised price targets on Amazon shares, to as much as $430, after the world's biggest online retailer company reported strong results for the third quarter.

The stock, which has already risen 32 percent this year, was trading around $356 before the bell, up from $332.21 at the Nasdaq close on Thursday before the results were announced.

Brokerage Raymond James raised its rating on the stock to "strong buy" from "market perform". Most other brokerages maintained the equivalent of "buy" or "hold" ratings.

"We're increasingly positive on Amazon shares, given strong revenue growth with accelerations in media and EGM (electronics and general merchandise), both in North America and International," J.P. Morgan analysts said in a research note, while sticking to their "neutral" rating.

Amazon reported its first quarterly revenue beat since the first quarter of 2012, as well as better-than-expected gross margins.

"...We see consistent margin expansion, continuing through at least 2014, helping support Amazon's seemingly lofty valuation," said Benchmark analyst Daniel Kurnos, who has a price target of $400 on the stock.

Many analysts characterized the company's holiday-quarter sales forecast of $23.5 billion to $26.5 billion as conservative. First-quarter sales rose 24 percent to $17.1 billion, helped by a 31 percent rise in North America.

In contrast, rival eBay Inc (>> eBay Inc) cited weak consumer confidence for its holiday quarter sales forecast that fell short of analyst expectations.

"Amazon appears to be gaining share at a more rapid pace while still investing heavily in tech and content, fulfilment capacity and international market development," Stifel Nicolaus analysts said in a note.

Expanding beyond retailing, Amazon has come out with products such as the Kindle Fire tablet, video and content subscription service Amazon Prime and the Amazon Web Services cloud computing platform for businesses.

This has elevated Amazon to the status of a major tech company along with Apple Inc (>> Apple Inc.), Google Inc (>> Google Inc) and Microsoft Corp (>> Microsoft Corporation).

Analysts at RBC Markets, who have an "outperform" rating on the stock, said Amazon's strong mobile positioning and infrastructure advantages that allow for fast delivery should allow the company to build on the 20 percent market share they estimated it already has in the United States.

Deutsche Bank analyst Ross Sandler said Amazon shares were "a core must-own" in large cap internet.

"It remains our top idea in e-commerce sector," he wrote, reiterating a "buy" rating.

(Reporting by Soham Chatterjee; Editing by Ted Kerr)