Billionaire activist investor Carl Icahn has filed a lawsuit against Occidental Petroleum, calling its proposed $57 billion takeover of Anadarko Petroleum "fundamentally misguided and hugely overpriced", writes Julia Martinez.

A lawsuit filed last week by several Icahn companies said Occidental "decided to go for growth-at-all-costs at the price of ballooning the company’s debt burden, rather than trying to maximise stockholder value prudently".