Singapore Airlines has bought a little bit more of Virgin Australia

The Merlion, Marina Bay Sands and the Singapore city skyline. Suhaimi Abdullah/Getty Images

Singapore Airlines has increased its holding in Virgin Australia to 23.11% from 22.91%.

The swaps deal was done for $3.18 million, according to an announcement to the Singapore exchange where the airline is listed.

The transaction comes at a time when the future ownership of Virgin is uncertain.

Its shares are trading at $0.362 today, almost 2% higher.

Air New Zealand is exploring options for its 26% slice of Virgin Australia, including a possible sale of all, or part, of its shareholding.

At $0.38 a share, the last price they traded at, the Air New Zealand holding is worth $348.5 million.

Virgin Australia is doing well, carrying more passengers, opening new routes, building revenue and getting the benefit of lower fuel costs.

The airline returned to profit, with better returns per seat, after a long battle with Qantas. Last month it posted a $62.5 million half year profit, its first since 2010, compared to a loss of $47.8 million the year before.

The other major shareholders are Etihad Airways (24%) and Virgin Group (10%).