BlackBerry subscriber numbers surged by 2.3m in the first quarter and Research in Motion’s profits more than doubled, but shares in the Canadian smartphone maker were marked sharply lower in after-hours trading because the outlook fell short of some analysts’ expectations.

RIM’s shares, which had risen roughly 20 per cent since early April, fell by $11.24, or 7.9 per cent, to $131.10 in after-hours electronic trading after closing at $142.34 on Nasdaq.