(For a Reuters live blog on U.S., UK and European stock markets, click LIVE/ or type LIVE/ in a news window) * FTSE 100 up/down 0.4%, FTSE 250 adds/off 0.5% March 10 (Reuters) - A decline in mining stocks led British shares lower on Wednesday, while energy stocks tracked a decline in oil prices on expectations of a rise in U.S. inventories. The blue-chip FTSE 100 index fell 0.4%, with mining stocks, including Rio Tinto, Anglo American and BHP being the biggest drags. oil producers BP and Royal Dutch Shell were also among the laggards. England’s COVID-19 test and trace system has not yet proven its worth as there is little evidence of its overall effectiveness, the British parliament’s Public Accounts Committee said, decrying the “unimaginable” costs of the programme. The domestically focused mid-cap FTSE 250 index fell 0.5%, dragged by consumer discretionary stocks. Restaurant Group rose 13%, as it said it was planning to raise 175 million pounds ($242.7 million) through a share sale after the Frankie & Benny’s owner posted a bigger loss due to a hit to its business from Britain’s latest round of lockdowns. Insurer Legal & General fell 0.5%, after a 3% dip in 2020 operating profit, hit by a slowdown in housebuilding and demand for life insurance products due to the pandemic.