By Ron Bousso LONDON (Reuters) – Harbour Energy’s Europe Chief Executive Phil Kirk will step down at the end of the month, after helping transform the company from a small North Sea oil and gas firm to the basin’s largest producer. Harbour, which is led by CEO Linda Cook, is unlikely to replace Kirk’s role, a company spokesperson told Reuters. “Phil has been instrumental in the building of Harbour Energy over the past years,” Cook said in a statement. Kirk will step down from his role on Feb. 28, the company said. Kirk founded Chrysaor in 2007, which with the backing of private equity firm EIG…