* Also wants fund to explain how it assesses climate risk
* Norway fund is world's largest sovereign wealth fund
* Graphic: http://tmsnrt.rs/2tskfub(Adds detail)
OSLO, June 28 (Reuters) - Norway's $1 trillion sovereignwealth fund, the world's largest, must assess how the plannedphase out of oil and gas exploration and production companiesfrom its investments will be conducted, the finance ministrysaid on Friday.
As part of Norway's efforts to shift its "rainy day" fundaway from oil, the country's parliament on June 12 adopted aplan to drop all dedicated oil and gas explorers and producers,as defined by stock market indices provider FTSE Russell, fromthe fund's benchmark index.
The fund can still invest in oil firms that have refineriesand other downstream activities, so-called integrated companiessuch as Royal Dutch Shell and ExxonMobil.
The finance ministry wants the central bank, which managesthe fund, to present a time schedule for the phase out by Sept.13 to the finance ministry, which will then establish its ownplan.
The fund has previously said that any divestments would takeplace gradually and over time.
Norway has said the decision is to reduce the exposure ofthe country's wealth to the risk of a permanent drop in oilprices, but environmental campaigners have seized on it as anexample of an investor turning away from the oil industry.Also on Friday, the finance ministry requested the centralreview and describe its efforts related to climate risk in thefund's investments by Dec. 1.
In particular, it wants the bank to describe how it assessesclimate risk across the portfolio, whether it is the companiesit is invested in, the real estate properties or its bondholdings.
(Reporting by Victoria Klesty and Gwladys Fouche; Editing byElaine Hardcastle)
