UPDATE 2-Miners end FTSE 100's three-day winning run

* FTSE 100 down 0.7%, FTSE 250 up 0.2%

* Miners biggest drags on main bourse

* Carmaker Aston Martin falls on forecast cut (Adds company news items, updates shares)

By Muvija M

July 24 (Reuters) - Miners dragged London's main index to its worst day in two months on Wednesday as iron ore prices fell after Vale prepared to resume operations at its Vargem Grande complex, while luxury carmaker Aston Martin lost a quarter of its value after cutting annual targets.

The FTSE 100 ended down 0.7%, lagging its European counterparts which held steady on hopes of more monetary stimulus following weak business growth data and signs of progress in U.S.-China trade talks. The FTSE 250 midcap index added 0.2%.

Vale SA said it had been authorised to partially resume dry processing operations at the complex in Brazil, months after the country's mining regulatory agency had ordered the company to halt operations there to guarantee the stability of its dams.

Rio Tinto was among the biggest fallers with a 4.6% drop, while Anglo American and BHP were also lower, as Liberum analysts downgraded the iron ore majors and flagged warning signs after rising iron ore port inventories.

Exporters also weighed on the index as sterling recovered after falling in the last session after Brexit hard-liner Boris Johnson won the leadership of Britain's Conservative Party to become the country's next prime minister.

Investors were quick to dump financial shares, spooked by Deutsche Bank's bigger than forecast quarterly loss of 3.15 billion euros. The UK's big banks RBS, Barclays , Standard Chartered and Lloyds Banking are set to report earnings next week.

MIXED BAG

Corporate earnings on Wall Street and in Europe have been largely positive this week.

However, data from Refinitiv highlighted the risk of an earnings recession, as earnings at constituents of the pan-European STOXX 600 index are now expected to decline this quarter, putting it at risk of back-to-back quarterly declines.

Among earnings-related moves on Wednesday, Aston Martin dropped 25.9% after it cut its 2019 volumes forecast, with sales to dealers in Europe down by almost a fifth in the first half.

The guidance cut from followed a disappointing quarterly update from German peer Daimler.

Pub operator Marston's slumped 12% after reporting like-for-like sales numbers that Peel Hunt analysts called "slightly worse than we expected".

Helping contain losses on the FTSE 100 was broadcaster ITV , which jumped 7% after it said a strong contribution to online revenue from reality show "Love Island" helped limit the decline in first-half ad revenue.

Event manager Informa rose 6.5% to its highest this year, after reporting strong half-year results.

Chemicals maker Croda, however, fell 3.3% as profit missed expectations with the U.S.-China trade war and new Chinese sales legislation having hurt demand at its personal care unit. (Reporting by Muvija M in Bengaluru; Editing by Shounak Dasgupta and Kirsten Donovan)