Negotiations about the sale by Murphy Oil of its Murco business in the UK, including its Milford Haven oil refinery, are in the final stages according to a number of reports.
According to Reuters oil entrepreneur Gary Klesch was in the final stages of exclusive talks with Murphy Oil and a decision on a deal would be made this week or early next week at the latest.
Neither the Swiss-based Klesch Group or Murphy Oil would comment.
Meanwhile Welsh newspapers quoted Wales Office minister Stephen Crabb as saying talks were coming to a head.
If a deal is not done, it is expected that Murphy will move to close the Milford Haven plant, putting most of its some 500 employees out of work. The plant is currently not buying crude oil, but recycling oil products to keep it operational.
Murphy has been seeking to sell the Murco business for more than three years and was close to a deal with a private equity fund in March before talks broke down.
It then started a 45-day consultation period in early April with staff and unions about closure of the oil refinery, but this was left open when it elapsed in May.
Last month Tom McKinlay, head of Murphy Oil’s UK operations, told staff he was taking a leave of absence to work on a management takeover.