* 3PAR says HP's offer likely to lead to superior offer
* If 3PAR endorses HP, it will give Dell 3 days to match
* 3PAR informs Dell it intends to talk with HP
* Dell shares slide 3 pct; 3PAR shares above HP offer
* Reuters survey sees final price at $29 per share (Adds link to Reuters survey of fund managers in para 8)
By Soyoung Kim and Noel Randewich
NEW YORK/SAN FRANCISCO, Aug 24 (Reuters) - 3PAR Inc said on Tuesday it will start merger talks with Hewlett-Packard Co after HP's $1.6 billion offer for the data storage company trumped a bid by its smaller rival Dell Inc.
3PAR has determined that HP's proposal was "reasonably likely" to lead to a superior offer over Dell's $1.15 billion bid and has informed Dell of its intention to enter talks with HP, the company said in a filing with the U.S. Securities and Exchange Commission.
If 3PAR's board endorses the bid by HP, it will give Dell 3 business days to sweeten its offer, 3PAR said in the filing, adding that it has not yet made such a determination.
The filing comes a day after HP offered to buy the high-end data storage company for $24 per share, topping Dell's bid by a third in a surprise move that could spark a rare bidding war in the technology sector.
3PAR said its board met on Monday to discuss HP's offer and decided to open its books to the company.
"3PAR intends to engage in discussions with HP promptly regarding its unsolicited acquisition proposal, and share nonpublic information with HP regarding 3PAR, in order to more fully evaluate HP's proposal with a view to establishing whether it is a 'superior proposal'," the company said in the filing.
Investors have been expecting Dell to come back with a more attractive offer, but the looming bidding war raised fears that it might overpay, as the world's two largest PC makers vie for a pivotal asset to broaden their scope.
A Reuters survey of 9 fund managers and analysts on Tuesday found most expect another bid or two, and a final price of around $29 per share -- nearly three times where they were before Dell's first public offer for $18 billion a share..
Earlier on Tuesday, Bloomberg reported Dell may convey a higher offer price within days to counter HP's offer, citing a person familiar with the matter, sending its shares down 3 percent. Dell was not available for comment.
3PAR shares rose 3.6 percent to $27.04, above the $24 a share HP has offered -- which was about 33 percent higher than Dell's $18 a share bid.
ENCROACHMENT
Tech giants such as HP and IBM Corp are expanding rapidly into new areas, hoping to offer more comprehensive products, but encroaching increasingly into each other's traditional markets.
3PAR is one of a few candidates that could help Dell expand from computers to corporate solutions in both software and hardware, but bids for the company already look expensive, said Jeffrey Fidacaro, an analyst at Susquehanna Financial Group, a market maker in shares of Dell.
"These are pretty high valuations to be paying for this asset, so now it comes down to who strategically needs this the most," Fidacaro added.
Dell's shares fell 3 percent, or 36 cents, to close at $11.59 on the Nasdaq stock exchange.
HP shares ended 1.7 percent lower at $38.39 on the New York Stock Exchange.
Bidding wars are rare in the tightly knit technology sector, where deals are often made behind closed doors, with a few exceptions such as the 2009 battle between Oracle Corp and IBM for Sun Microsystems. Oracle eventually bought the computer maker for $7 billion.
For 3PAR, a deal with a large company such as Dell or HP would give it a broader sales reach, helping it compete against rival EMC and smaller players such as Isilon Systems Inc and Compellent Technologies Inc.
IBM, HP and Oracle have been boosting investment in cloud computing and virtualization technology, which allows users to access data and software over the Internet and corporate networks.
3PAR is advised by veteran technology banker Frank Quattrone and his outfit Qatalyst Partners. Credit Suisse Group AG is advising Dell and JPMorgan Chase & Co advises HP. (Reporting by Soyoung Kim and Liana B. Baker and Yinka Adegoke in New York and Noel Randewich in San Francisco; Editing by Gary Hill and Dhara Ranasinghe)