Valuable broadband and networking patents developed by bankrupt Nortel Networks go up for sale next week, with tech giants like Google, Apple and Intel heading the list of would-be buyers.

In one of its last asset sales in a drawn-out bankruptcy break-up, Nortel is selling 6,000 patents and patent applications, ranging across its whole spectrum of expertise in wireless, data and optical networking, voice, Internet, semiconductors and other technologies.

The sale could fetch $1.5 billion, said Josh Walker, CEO of Lex Machina Inc, which consults on intellectual property litigation. This is one of the largest and one of the most strategically significant ones, he said.

The most prized patents in the collection relate to next-generation mobile broadband technology used in emerging 4G standards such as long term evolution (LTE).

Mike Lazaridis, the co-chief of Canada's Research In Motion, once described these patents as a national treasure.

But RIM will likely be outbid by deep-pocketed mobile companies including Google and Apple.

A source at chipmaker Intel called the portfolio a gold mine for its own push into mobile. Several sources have said likely bidders also include Sweden's Ericsson and U.S.-based RPX Corp, which licenses patents on behalf of member clients for a fee.

Chinese network equipment maker ZTE has also expressed interest in the LTE portion.

The auction, almost certainly the largest public sale of its kind, comes amid strong mobile industry growth -- and soaring litigation -- as relative latecomers Apple and Google seek to bolster weaker collections of patents versus rivals.

Walker said a $1.5 billion price tag was not excessive, considering licensing and royalty deals can cost a company between $500 million and $1 billion.

The sale of Nortel's patents could take days to thrash out and must then be approved by a Delaware bankruptcy court on July 11. The court will likely hear objections from losing bidders and companies that reached licensing deals with Nortel while it was solvent, such as Microsoft .

A NEW WORLD

In earlier days, tech companies would quietly hash out licensing deals to share their technical know-how, and those with the most patents got the best terms.

This history makes it easier to value the radio patents, which Morgan Keegan analyst Tavis McCourt described as a much more mature market for royalties than exists for some of the other Nortel patents.

But the ground rules are being rewritten as smartphones and tablet computers promise new riches and bring new players into the wireless industry.

You need to add in a fear premium from most of the people you hear that are attached to this auction, said a source close to the situation. I think for certain people it would be a bad thing if other people got their hands on these patents.

Google opened bidding in April with a $900 million stalking horse bid, and said it hopes the patents will ward off litigation from more established rivals.

Its Android mobile software has attracted a lawsuit from Oracle, while handset makers using the software have also been sued by both Apple and Microsoft, which claims an existing, perpetual license to Nortel patents.

Microsoft receives money from deals reached with some Android handset makers but is pressing for more.

The industry's fear of litigation could help RPX, which can reduce risk for its customers -- including major chip and handset makers, network builders and carriers -- by ensuring they are licensed to use the related technologies.

The patent sale is a last gasp for Nortel, which was once Canada's biggest company by market capitalization before imploding as the tech bubble burst. It filed for bankruptcy protection in January 2009.

Nortel raised around $3.2 billion for creditors by selling business units since then.

The bankruptcy case is Nortel Networks Inc., 09-10138, U.S. Bankruptcy Court, District of Delaware (Wilmington).

(Additional reporting by Tom Hals, Nadia Damouni, Tarmo Virki and Noel Randewich; editing by Janet Guttsman)