* Blackstone, Blue Water offer all, or parts, of Siccar Point
* Sale of parts of portfolio more likely - sources
* Sources value portfolio at up to $3 bln
By Shadia Nasralla and Ron Bousso
LONDON, Oct 31(Reuters) - Bids for North Sea oil and gas firm Siccar Point, backed by private equity groups Blackstone and Blue Water Energy, are due on Nov. 7 and are likely to target specific assets rather than the whole company, four industry sources said.
The list of bidders is expected to include EIG-Harbour Energy backed Chrysaor that is currently the largest producer in the North Sea, private equity fund HitecVision, Royal Dutch Shell, BP , Equinor, Suncor, CNOOC and Repsol, the sources said.
One source valued the whole company at up to $3 billion and another source said it was unlikely to fetch more than $2 billion.
The sale process comes as some private equity-backed North Sea companies largely abandon earlier plans to publicly list amid a sluggish recovery in oil prices.
Siccar Point is wooing potential buyers of its assets with just under 600 million barrels of oil equivalent (boe) of resources and reserves, including more oil than gas, a sale document showed.
Such yet-to-be-exploited barrels can be attractive to some of the private-equity backed firms that have bought aging North Sea assets from oil majors in recent years and are looking for future growth ahead of a potential stock market listing or sale.
Siccar Point sees its output reaching about 80,000 barrels of oil equivalent per day (boed) by about 2027 from currently just over 10,000 boed. Beyond this, output will mainly be boosted by the Cambo development.
Among other smaller stakes, Siccar Point holds 70% in Cambo field alongside Shell, 11.8% in the BP-operated Shiehallion field and 20% and 9%, respectively, in Equinor-operated Rosebank and Mariner fields.
The portfolio offers production and exploration opportunties, including 1.4 billion boe in yet-to-be drilled prospects and leads in the West of Shetlands area, where majors like BP, Shell and Equinor are boosting North Sea production.
Siccar Point would offer a potential buyer $2 billion in so-called tax losses in Britain, which would "shelter profits with no tax payments expected until (the) late 2020s," according to the sale document sent to potential buyers.
The sellers have said in sales documents they would prefer to sell all of Siccar Point, but would consider bids for separate packages of assets. The document offered five separate packages to bidders.
Rothschild and Lambert Energy are advising Siccar Point on the sale.
HitecVision, Blackstone, EIG/Harbour, Chrysaor, Equinor, BP, Shell, Rothschild and Lambert declined to comment. Suncor and CNOOC did not immediately respond to a request for comment (Reporting by Shadia Nasralla, editing by Deepa Babington)