Private equity leviathan 3i said its investments are stabilising or improving while the pipeline of investment opportunities looks promising.Investment in the second quarter of 2010 totalled £105m, compared to £79m in the second quarter of 2009. Of the £105m invested, £70m was pumped into the existing portfolio with the remainder going into the group's first investment in Vedici.Realisation proceeds (excluding funds managed or advised by 3i) were £79m, versus £163m a year earlier. The largest of the realisations was the sale of Kneip, which generated £29m of proceeds. Realisations exclude the partial realisation of Inspicio, which was signed in the period but is not expected to complete until the end of the summer, generating proceeds of around £120m.At the end of June the group had cash, cash deposits and undrawn committed facilities of £2.36bn, down from £2.73bn at the end of the first quarter.Net debt increased from its year end level of £258m to £325m, recognising the net outflows from investments and realisations, together with other operating expenses.