Investor Elliott Management has again suggested that BHP should review its dual-listed structure and reorganise as a single company in Australia to add over $22 billion in value for shareholders.

It is a view that the company’s chief executive officer Andrew Mackenzie has disagreed with in the past. The CEO said late last year that costs would probably outweigh the benefits, and estimated a cost of $1.3 billion.

According to Elliott’s report, however, which was created under commission by FTI Consulting,  reorganising BHP’s head operations into a single Australian entity would cost only $391 million.

BHP’s dual-listed structure, a result of the 2001 merger between the Australian half of BHP and the UK half of Billiton, means BHP Billiton as a whole has two HQs (Melbourne and London) and two market listings, but a single management and board.

FTI’s study stated that restructuring into single listing could result in a $14.1 billion increase in market valuation and a return of $8.7 billion through improved tax credit efficiency.