The board of Karoon Energy (ASX:KAR) approved an on-market share buyback of up to 20.8 million shares, or roughly $22 million, the first phase of the planned $75 million additional buybacks for this year, according to a Monday filing with the Australian bourse.

The company has bought back and canceled 52.3 million shares for $50 million in the past eight months, the filing said.

Completion of the first phase of the buyback is expected to bring the total invested in Karoon shares to $72 million, equivalent to about 10% of issued capital, per the filing.

Shares fell 2% in afternoon trade Mon onday.