Heritage Oil is to list on the main market in London before the end of the month and, with a market capitalisation of some C$1.3bn (£652m), will enter the FTSE 250.

A notice of intention to list will be issued this week on the proposal that Paul Atherton, the chief financial officer of Heritage, expects to be endorsed overwhelmingly. Shares are likely to be admitted for trading on March 26 with the listing sponsored by JPMorgan Cazenove.