UPDATE 2-Minerva NAV rises in robust London markets

(Adds analyst comments, updates shares)

LONDON, Sept 10 (Reuters) - Minerva Plc (MNR.L) posted a 5.3 percent rise in its net asset value on Monday and said it expected to make further progress as London property markets remained robust. Minerva, whose portfolio focuses on London, said its net asset value - a key performance gauge for property companies -- was 327.9 pence per share at end-June compared to 311.5p the year before.

Rents and demand for office space in London are surging, offsetting an expected slowdown in property price rises, and changing the capital's skyline as developers go upwards with ever-taller buildings.

Minerva's portfolio includes the 550,000 square feet St Botolph's office and retail development in the City of London and the Park Place retail centre in Croydon, south London.

KBC analyst Keith Crawford cut his forecasts and rating on the stock to reduce from add, citing unease about the group's long-term projects.

"It is hard to escape some unease about shorter run trends in the further off schemes in EC3 and Croydon we have therefore initially reduced by 10 percent across off the board," he said.

Shares in Minerva, which have underperformed the UK real estate sector .FTASX8730 by 4 percent over the last 12 months, were down 2.9 percent at 260.5 pence by 0820 GMT, valuing the group at around 420 million pounds ($849.2 million).

Minerva, which dropped plans last year to build what would have been the City of London financial district's biggest skyscraper, posted a pretax profit for the first-half of 16.3 million pounds, compared to a loss of 6.9 million pounds in 2006.