INTERVIEW-Virgin's Branson still keen on Northern Rock and bmi

* Virgin still keen on buying bmi and Northern Rock

* Branson says govt made mistake over bank sale

NEW YORK, June 22 (Reuters) - Virgin Group is keen on buying long-running takeover targets Northern Rock and bmi and is open to discussions on both, President and founder Richard Branson said on Monday.

Speaking to Reuters on a flight between London and New York, Branson said Prime Minister Gordon Brown had made a "huge mistake" in not selling him collapsed mortgage bank Northern Rock before it was nationalised in 2007.

However, he said subsidiary Virgin Money remained open to a deal.

"If the government chose to sell it, we would hope to take advantage ... we do think the timing is very good to have a brand people trust to get into banking," he said, adding that Virgin Money would also look at other opportunities to grow by acquisition.

"We are not going to give up. Over the next few months something should come up."

Branson said he expected to have discussions with German carrier Lufthansa (LHAG.DE) over its British airline bmi [BMID.UL] -- long a target for Virgin Atlantic [VA.UL] due to its London Heathrow take-off and landing slots and short-haul focus.