* FTSE 100 up 0.7%, FTSE 250 adds 0.5%
Aug 25 (Reuters) - The FTSE 100 rose for a second straight session on Tuesday as a pledge by Washington and Beijing to stand by their Phase-1 trade pact lifted global sentiment, while technology firm Aveva jumped after signing a $5 billion takeover deal.
The export-heavy FTSE 100 added 0.7% and the mid-cap FTSE 250 0.5%, with China-reliant miners and Asia-focussed banks among the early gainers.
Aveva Group rose 2.3% to the top of the FTSE 100 as it said it would buy OSIsoft, a privately held maker of industrial software used to manage plants and factories, for an enterprise value of $5 billion.
AstraZeneca Plc rose 0.6% after launching a trial for an antibody-based treatment for COVID-19.
The drugmaker logged its best session in a week on Monday as a report said the U.S. government was considering fast-tracking its experimental vaccine, already among the most advanced vaccine candidates.
Retailer DFS Furniture Plc jumped 13.5% after saying its performance over the last six weeks was significantly above its initial expectations.
(Reporting by Sagarika Jaisinghani in Bengaluru; Editing by Subhranshu Sahu)