John Laing Infrastructure announced it is reviewing several potential investments as it reported two per cent underlying growth in the value of its portfolio in the first quarter.The portfolio value increased to £799m by the end of March, up from a rebased £783.6m at December 31st.Net asset value, excluding the £24.9m dividend for last year which will be paid on May 19th, was £801.7m."JLIF's start to 2014 has been one of continued progress with our portfolio growing in line with our expectations," said Chairman Paul Lester."The secondary market remains active with JLIF currently reviewing a number of investment opportunities. We look forward to building on JLIF's solid start to the year and are optimistic about JLIF's prospects for 2014. "As of 12:57, the share price was unchanged at 114.30p.WS