"Any reason why they're looking to pursue this buyback instead of pay down debt".
The answer
@NoLeafClover is YES: PRN's management is using the free cash from DDH1 (as a former DDH1 shareholder, your former monetary asset) to support its shareprice.
The takeover involved PRN offering DDH1 holders either cash or a mix of cash and shares or all shares. However as the pool of available cash was exhausted quickly by those DDH1 holders wanting cash only, PRN backfilled the gap with additional PRN shares which unhappy DDH1 holders are now keen to offload.
So to support its shareprice, PRN is now mopping up those additional shares with what was formerly your money. Still thinking about investing in PRN??? Just think about "the high level of debt" and what it means in an increasing interest rate environment. As an aside why not ask PRN's CFO what its Corporate Credit Rating is and its interest spread.
I've seen some dodgy deals but this is a cracker.
(20min delay)