Santos chief executive Kevin Gallagher says his infrequent late night serenades on the bagpipes sound more like a "squealing pig" these days than the award-winning renditions of the Flower of Scotland he belted out to win junior competitions in his younger days in Scotland.

He's had little time for musicianship. Santos, the corporate jewel of South Australia, has rebuffed its second big takeover bid in three years after rejecting a $14.4 billion proposal from United States private equity giant Harbour Energy on May 22. Gallagher says he's now pursuing a growth strategy after vigorous cost-cutting to revive the company following some bleak times before he arrived in early 2016.