Iraq minister says BP, CNPC to invest $50 bln

* $25 bln in investment costs, $25 bln in operating costs

* BP says only $15 bln over life of contract

BAGHDAD, Nov 3 (Reuters) - Total investment by British oil company BP (BP.L) and its Chinese partner CNPC in Iraq's supergiant Rumaila oilfield will amount to $50 billion, Iraqi Oil Minister Hussain al-Shahristani said on Tuesday.

But BP's chief executive, Tony Hayward, put the investment over the 20-year lifetime of the contract at $15 billion and a statement from BP carried the figure. [ID:nL3558520]

"The total investment of the project is $25 billion as investment cost and $25 billion as operative costs for the period of developing the field," Shahristani told Reuters, when asked to clarify the $50 billion figure.

Asked about Shahristani's remarks, a BP spokesman said he could not explain the $50 billion figure and declined immediate comment on likely operating costs.

On Monday, Shahristani said Italian oil major Eni (ENI.MI) and its partners would invest $35 billion in the Zubair oilfield. But ENI, which signed an initial agreement for the field, has said it would invest $10 billion.

The company declined to comment on the much higher figure given by the Iraqi oil minister. (Reporting by Ahmed Rasheed; Writing by Michael Christie; Editing by William Hardy)