** Archer Materials AXE.AX rises 8% to A$0.27; marks biggest intraday pct gain since April 11

** Semiconductor firm signs agreement with UK graphene-based electronics company Paragraf to advance development of Archer's biochip potassium ion sensor to test for chronic kidney disease

** Says deal to be in two stages at total estimated cost of A$450,000 ($288,810)

** About 526,535 shares traded vs the 30-day avg

** Stock trims YTD losses to 53.5%

($1 = A$1.5581)

(Reporting by Sneha Kumar in Bengaluru)

((Sneha.kumar@thomsonreuters.com;))