* Defence-linked firm Zhenhua aims to finalise deal by June
* Deal would add 16 mln T oil equivalent to annual Zhenhua output
* Bangladesh to pursue bid only if fields judged viable -minister (Adds detail, response from Chevron, Zhenhua, comments from Bangladesh energy minister)
By Chen Aizhu and Ruma Paul
BEIJING/DHAKA, Feb 22 (Reuters) - China's state-run Zhenhua Oil has signed a preliminary deal with Chevron to buy the U.S. oil major's natural gas fields in Bangladesh that are worth about $2 billion, two Beijing-based Chinese oil executives said.
Zhenhua is a subsidiary of China's defence industry conglomerate NORINCO. A completed deal would mark China's first major energy investment in the South Asian country, where Beijing is competing with New Delhi and Tokyo for influence.
Bangladesh, though, holds the right of first refusal on the assets and could block the transaction. The country, via its national oil company Petrobangla, is keen to buy the gas fields and is talking to international banks to raise financing, according to a banking source familiar with the process.
Bangladesh is in the process of hiring global energy consultant Wood Mackenzie to assess the fields' reserves before placing a formal bid to buy the assets, two Bangladesh sources familiar with the matter told Reuters.
The Bangladesh sources said they were not aware of Zhenhua Oil's competing interest in the Chevron fields.
"As this project is in the process of commercial discussions, we can't comment based on our company policy," said Zhang Xiaodi, Zhenhua Oil's spokesman.
Zhenhua Oil is a small oil and gas explorer that despite its connections to China's defence industry is dwarfed in comparison to state energy giants PetroChina and Sinopec . It is trying to formalise its deal with Chevron by June, after the two companies signed a preliminary pact in January, the two senior oil executives told Reuters.
Zhenhua will partner with China Reform Holdings Corp Ltd, an investment vehicle under the State-owned Assets Supervision and Administration Commission (SASAC). Zhenhua will hold 60 percent of the deal and China Reform 40 percent, the two executives said.
The executives declined to be named as these discussions were not public.
Chevron, in an e-mailed statement, confirmed that it was in commercial discussions on its Bangladesh assets, but would not comment further as a matter of policy.
Chevron had said in October 2015 that it planned to sell about $10 billion worth of assets by 2017 including geothermal projects in Indonesia and the Philippines and gas fields in Bangladesh amid a prolonged slump in energy prices.
Bangladesh knows that Chevron is in talk with global companies, but has no specific knowledge about Zhenhua's interest, said Nasrul Hamid, state minister for power, energy and mineral resources.
"This is Chevron's matter. We'll not interrupt but we are supposed to get the first priority," he said when asked if Bangladesh would try to block the China deal.
"We will place a formal bid only if the project is viable," Hamid said.
Chevron sells the entire output from its three gas fields - Bibiyana, Jalalabad and Moulavi Bazar, which account for more than half of Bangladesh's total gas output - to state energy firm Petrobangla under a production sharing contract.
If the Bangladesh deal materializes, it would hand the Chinese firm 16 million tonnes a year of oil equivalent output, including both natural gas and condensate, a scale that would make it China's fourth-largest oil and gas producer, the two Chinese executives said.
Reporting by Chen Aizhu in BEIJING and Ruma Paul in DHAKA; Additional reporting by Anshuman Daga in SINGAPORE; Editing by Tom Hogue