Abu Dhabi, Reuters—Asian and Western firms have bid to help operate the United Arab Emirates’ (UAE) biggest oilfields after a deal with oil majors expired this year, but the Gulf Arab state is yet to decide whether to let Asian oil buyers in for the long haul, sources said.

A final decision on the winning firms is unlikely before early 2015 as political leaders in Abu Dhabi, the capital of the UAE, weigh whether to bring in Asian firms or stick with old partners, industry and diplomatic sources said.

At least one oil major, ExxonMobil, appears to have decided against bidding, the sources told Reuters.

ExxonMobil, Royal Dutch Shell, Total and BP have each held 9.5 percent equity stakes in the Abu Dhabi Company for Onshore Oil Operations (ADCO) concession since the 1970s. Portugal’s Partex had a 2-percent stake, and the rest was held by state run Abu Dhabi National Oil Company (ADNOC).

After the deal expired in January, ADNOC took 100 percent of the concession. Shell, Total and BP have made their new bids, which are being evaluated by Abu Dhabi, the sources said.

Exxon, however, did not bid for the ADCO concession after it renegotiated a better deal for the Upper Zakum offshore oilfield, which it has been operating with ADNOC and Japan’s Inpex since 2006, two sources said.

The US major pulled out its staff from the ADCO fields earlier this year, a sign that it has dropped out of the race, sources say.

“Exxon has pulled its folks out while others kept their people. [It is] 95-percent [sure] Exxon has decided not to bid,” one source told Reuters.

“They are going to make, what, two or three US dollars a barrel? So they probably said: ‘Why have two projects in the UAE?’,” the source said.

Exxon said its ADCO concession expired on January 10 but declined to comment about its staff and future plans.

Exxon’s exit may improve the chances for the other three former partners and pave the way for newcomers to join in.

US firm Occidental Petroleum Corp, Italy’s ENI , China National Petroleum Corporation (CNPC), Norway’s Statoil, Japan’s Inpex and Korea National Oil Corp have bid for the new deal, three sources told Reuters.

Rosneft has been invited to bid, but it was not clear whether Russia’s top oil company has submitted an offer, two industry sources said.

“Abu Dhabi’s new partners are expected to be selected in early 2015. The evaluation process is underway,” one industry source said.

The onshore fields produce 1.6 million barrels per day (bpd), over half UAE’s oil output.

The UAE oil minister said in January Abu Dhabi has received strong interest from international firms to participate in the ADCO fields with revised terms.

ADNOC did not respond to Reuters emails and calls for comment. A CNPC official said the Chinese company has bid to operate the ADCO fields, but he knew no further details.

None of the remaining companies vying to be part of the next phase of development would comment on the situation.

Western oil majors have partnered Abu Dhabi for decades but several Asian energy companies are keen to secure stakes in fields that supply the growing Asian market.

That would offer a chance for UAE to strengthen political ties with its biggest oil buyers such as China, South Korea and Japan.

“The [UAE] leadership is turning eastwards more than before,” said Valérie Marcel of think tank Chatham House.

“We also know that the leadership wants new types of contracts, which encourage oil companies to invest more of their technology. These forces push Abu Dhabi towards new partners and new terms.”

Industry observers say any changes in the concessions would be made at the highest decision-making body for the oil and gas industry, the Supreme Petroleum Council. They say there is a difference in opinion inside the SPC over whether to stick with western companies, or make room for newcomers from Asia, while some would like to see ADNOC operating the fields alone.

“At the end of the day it will be the political decision of the leadership in Abu Dhabi on which company will take what,” a diplomatic source said.