LONDON (Reuters) - Qatar is preparing to issue a tender for energy firms seeking a stake in its gas expansion project, drawing interest from long-standing partners as well as newcomers Chevron, Norway’s Equinor and Italy’s Eni, industry sources said.

FILE PHOTO: Cars are parked outside the headquartes of Qatar Petroleum in Doha, Qatar, July 8, 2017. REUTERS/Stringer/File Photo

Plans to expand Qatar’s liquefied natural gas (LNG) facilities, already the world’s largest, by more than a third in the next five years are considered one of the most lucrative investments in the rapidly growing global gas market.

Competition is expected to be fierce.

The huge interest underscores how successfully the small Gulf country positioned itself in the face of a boycott imposed in 2017 by Saudi Arabia, the United Arab Emirates, Bahrain and Egypt, which accuse Doha of supporting terrorism and their enemy Iran. Qatar denies the charge.

Qatar’s state-run oil and gas company has in recent weeks held talks with several foreign energy firms that want to help build the new LNG facilities, four sources close to the discussions said.

Qatar Petroleum (QP) is preparing to issue a tender seeking partners to invest in the construction of a fourth LNG train, or production line, that will see its capacity grow to 110 million tonnes a year (mtpa) from the current 78 mtpa.

The four companies that hold stakes in Qatar's existing LNG facilities - Exxon Mobil XOM.N, Royal Dutch Shell RDSa.L, France's Total TOTF.PA and ConocoPhillips COP.N - are widely expected to bid, according to the sources.

Exxon, Shell, Total and Conoco declined to comment. Total and Conoco have said in the past that they hope to play a role in the expansion.

A number of newcomers are also set to join the race.

Officials from Chevron CVX.N, the second-largest U.S. oil company, have held talks in Doha in recent weeks and are considering bidding for a stake in the expansion, the sources said.

A Chevron spokeswoman declined to comment.

Norway's national oil company Equinor EQNR.OL is considering submitting an offer as it seeks to expand its global LNG operations, which have lagged those of rivals, sources close to the company said.

An Equinor spokesman said: “We continue to assess business development opportunities globally, but we don’t have any comments on specific regions.”

Italy's Eni ENI.MI plans to play a role in the project, Chief Executive Claudio Descalzi recently said. Eni and QP bolstered ties in recent years after QP acquired from Eni stakes in three offshore blocks in Mexico.

One Chinese state-owned company is also in the process, the sources said.

Brazilian oil and gas company Petrobras considered bidding but in recent weeks decided against it, the sources said.

Petrobras did not respond to a request for comment.

(Graphic: LNG supply and demand - tmsnrt.rs/2mQuxSY)

“Qatar’s planned LNG expansion is one of the global standout opportunities in 2019,” consultancy WoodMackenzie said.

“Partner selection is ongoing, and we expect awards to be made in advance of FID (final investment decision) in 2020 ... The upstream segment alone is a world-class asset and operators will struggle to find other low-cost opportunities of this scale,” it added.

“QP is unlikely to sole risk the development and will seek partners. However, suitors will need to prove they can add value to win a stake. We expect to see all the incumbents, primarily the majors, jostling for position.”