Investment group 3i Infrastructure said it was on track to meet its annual dividend target, after its portfolio performed well in the fourth quarter.The FTSE 250 group, which targeted an annual return of 10% and annual distribution of yield of 5.5% of opening assets, said it expected its total return to be "very strong" for the year to 31 March.In a statement released on Tuesday, the London-listed company said the income generated by its European portfolio over the financial year amounted to £79.5m, a 1.73% decline year-on-year."The portfolio has continued to perform well in the final quarter of the year, generating good levels of income which will support the delivery of the company's dividend objective this year," said group chairman Peter Sedgwick.3i said it would review its objectives in order to set a "sustainable total return target and a revised dividend policy" that will take into account tougher market conditions.A challenging trading environment has made it harder for the group to invest in large infrastructure businesses at total returns and yields in line with current targets.Meanwhile, the group confirmed it was on track to complete the acquisition of a 45% stake in both Oiltanking Terneuzen and Oiltanking Ghent for €111m (£80.6m), with the deal set co be completed in May."This new core infrastructure investment was particularly positive for the company against the backdrop of a highly competitive market," Sedgwick said.3i shares were up 0.34% to 160.75p at 10:30 on Tuesday.