Portfolio Update

BLACKROCK WORLD MINING TRUST plc
All information is at 30 April 2012 and unaudited.

Performance at month end with net income reinvested
                                 One    Three      One     Three    Five
                               Month   Months      Year    Years   Years
Net asset value* (undiluted)   -0.8%    -7.9%    -16.9%    85.5%   33.1%
Net asset value* (diluted)     -0.8%    -7.9%    -16.9%    85.5%   37.5%
Share price*                   -0.7%    -3.5%    -14.6%    84.7%   33.4%
HSBC Global Mining Index        2.2%   -11.1%    -24.4%    53.5%   40.4%
Sources: BlackRock, HSBC Global Mining Index, Datastream

*Net asset value and share price performance includes the warrant reinvestment,
assuming the 2004 and 2006 bonus warrant entitlement per share was sold and the
proceeds reinvested on the first day of trading.

At month end
Net asset value           Including Income            Capital Only
Undiluted/diluted:                 754.60p*                745.12p
*Includes net revenue of 9.48p

Share price:                       668.00p
Discount to NAV**:                   11.5%
Total assets:                   £1,404.30m
Net yield***:                         2.1%
Gearing:                              5.0%

Ordinary shares in issue:          177,287,242
Ordinary shares held in Treasury:   15,724,600

** Discount to NAV including Income.
*** Based on final ordinary dividend of 14.00p per share in respect of the year
ended 31 December 2011.

Sector                   % Total    Country Analysis          % Total
                          Assets                               Assets

Diversified                 40.9    Global                       44.2
Base Metals                 20.4    Latin America                18.8
Industrial Minerals         13.8    Australasia                  11.6
Gold                         9.2    Other Africa                 11.1
Silver & Diamonds            8.4    South Africa                  6.2
Platinum                     2.8    Republic of Congo             1.3
Energy Minerals              1.8    USA                           1.0
Net current assets           2.7    Emerging Europe               1.2
                           -----    Democratic Republic of Congo  0.9
                                    Canada                        0.6
                           100.0    Indonesia                     0.3
                           =====    Mongolia                      0.1
                                    Net current assets            2.7
                                                                -----
                                                                100.0
                                                                =====

Ten Largest Investments                      % Total
                                              Assets
Company
Rio Tinto                                        9.1
BHP Billiton                                     8.2
Vale                                             7.0
Glencore Finance (Europe) 5% 31/12/14            5.9
Minas Buenaventura                               4.4
Iluka Resources                                  4.3
First Quantum Minerals                           4.2
Teck Resources                                   3.8
Industrias Penoles                               3.5
Fresnillo                                        3.5

Commenting on the markets, Evy Hambro, representing the Investment Manager
noted:

Performance
Commodity demand fears have thus far looked to be overstated, as steel
production in China and other demand side indicators have held comparatively
firm.  Chinese steel production in March, for example, ran at an annualised
rate of 725 million tonnes, the second highest figure on record and up 3.1%
from February's figure (Source: China's National Bureau of Statistics).

The strength of Chinese steel activity has been reflected in the resilience of
the iron price. Spot prices in China have held firm above the $140/tonne level
all year (MB China 63.5% Fe; source: CLSA). Supply challenges have also played
a crucial role in keeping the dynamics underpinning prices constructive. Iron
ore production growth faces significant challenges in our view, not least
infrastructural (the ease with which ore can be transported from mine to
consumer). But, as in the early part of 2011, it has been adverse weather
conditions (cyclones in the Pilbara region of Western Australia, for example)
that have driven near term supply shortfalls in iron ore. Industry heavyweights
Vale, BHP Billiton and Rio Tinto (who together supply ~64% of the world's
seaborne iron ore market) reported a 12.4% decline in their combined iron ore
production for the first quarter this year versus the final quarter of last
year due to weather related obstacles.

Supply side challenges in the mining industry continue to be underestimated by
the market in our view. Industry participants are, unsurprisingly, more
cognisant and the message was highlighted at the CESCO copper conference hosted
in Chile in April at which predictions for another year of copper market
deficit were reinforced and the likelihood of continued mine disruptions
(whether linked to labour disputes, weather conditions or technical problems)
was a recurrent theme. 

BHP Billiton has invigorated an important debate about mining company strategy.
The mining giant has indicated that their capex plan is 'flexible'. The
messaging marks the first clear attempt by a major to address investor concerns
about capital allocation in the sector. Capital discipline is likely to be key
to mining share performance as shareholders have made plain their desire for
higher pay-outs and prudent capital spending from mining companies.

Strategy/Outlook
The global macro-economic outlook and fragile investor sentiment continue to
drive the near-term performance of the mining sector.

Mining company valuations look attractive across a variety of metrics. Balance
sheets have been bolstered by more careful management and record cashflow
generation. Mining managements have also shown themselves more willing to share
that balance sheet strength with investors through dividends and buybacks, a
trend they would do well to continue.

17 May 2012

ENDS

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terminal).  Neither the contents of the Manager's website nor the contents of
any website accessible from hyperlinks on the Manager's website (or any other
website) is incorporated into, or forms part of, this announcement.