Miners, Ashtead support UK shares; AstraZeneca gains

London's FTSE 100 edged higher on Tuesday with tool hire firm Ashtead gaining after an upbeat earnings report and miners boosted by a rise in copper prices driven by expectations of a global shortfall in production.

The miner-heavy main index was up 0.1% while the FTSE 250 midcap index lost 0.2% by 0708 GMT. Ashtead rose nearly 3%, topping the FTSE 100 leader-board, while miners were up 1% as a key mine in Chile halved output due to a strike.

Drugmaker AstraZeneca was the biggest boost to the FTSE 100 with a 1.1% rise after its cancer medicine Lynparza was approved as a first-line maintenance treatment for a type of advanced ovarian cancer by the European Commission. Rival GlaxoSmithKline also climbed. Market focus is gradually shifting to a two-day meeting of the U.S. Federal Reserve, with market pricing showing investors expect Wednesday's policy statement to open the way to a cut in interest rates by the central bank next month.