UBS AG laid out ambitious plans to restore the troubled Swiss bank to profitability, but struggled to convince investors who worried that new management still faces an uphill battle in turning the group around.

In his first major presentation since taking the helm in February, Chief Executive Oswald Grübel set a target of annual pretax profit of 15 billion Swiss francs ($14.89 billion) within three to five years. But he warned that a full turnaround would still take some time.