Norwegian oil firms Statoil ASA (NYSE: STO) and Det Norske Oljeselskap ASA are looking at more acquisitions after recent deals, their chief executives told Reuters, hunting for bargains after a plunge in energy prices.

Statoil last week bought an 11.9% stake in Sweden's oil firm Lundin Petroleum AB for $540 million, increasing its dominance on the Norwegian continental shelf where it already operates more than 70% of Norway's oil and gas output.

"We have done a transaction with Lundin, and we are of course monitoring other possibilities closely," Statoil CEO Eldar Saetre said in an interview, adding that Statoil has no current plans to raise its stake in Lundin.

"It is most likely that this [mergers and acquisitions] will increase," he said, speaking generally about the sector.

Last year saw a flurry of deals in Norway's biggest industry, with private equity investors buying up assets, betting on a recovery in crude prices, from energy firms happy to generate some cash.

The price of Brent crude is down 77% since June 2014, putting pressure on the budgets of energy companies but offering scope to pick up assets at attractive prices for those bold enough to bid.

Norway's Det Norske, controlled by Norwegian billionaire Kjell Inge Roekke, has been another active buyer.

The E&P company bought the Norwegian units of Marathon Oil Corp. (NYSE: MRO), Svenska Petroleum Exploration AB and Premier Oil Plc's over the past 18 months.

"We want to play an active role in this market," Det Norske CEO Karl Johnny Hersvik told Reuters on the sidelines of a company investment seminar. "We are looking for further opportunities."

Smaller player OKEA, a private-equity backed Norwegian newcomer which this month took over a 60% stake in a North Sea oil field from Repsol SA of Spain, said it was looking at more deals this year.

"We think we can bring in more money as we make more good deals ... I hope that we can make one or two more deals in 2016," OKEA partner Erik Haugane told Reuters.

"Changes like this [in the oil price] is a catalyst for action. Some will buy more resources like we do, while others will clean out their portfolio to focus their business," he added.