German engineering and electronics group Siemens has disappointed investors by reporting a much smaller than expected rise in its fourth quarter profits and has warned of a "year of challenges".

Its net profit of 53m euros ($53.3m; �33.6m) was below the average forecast of 256m euros but was up from a 1.1bn loss in the same period last year.

"As the company doesn't expect significant improvement in overall economic conditions, and had made major disposals of businesses, the management anticipates declining business volume for Siemens in the coming year," it said in a statement.

Shares had fallen by 5.6% to 42.15 euros at 1201 GMT in response.

The conglomerate's wide range of operations - spanning power stations, trains, medical equipment, telecoms networks and mobile phones - have kept it afloat as the global economy struggles.

Sell-off boost

The company said only two of its units would not meet their earnings targets.

Core earnings in the three months to September came in at 176m euros, well below analysts forecasts of between 308m and 675m.

The results were helped by the disposal of assets, which raised 442m euros.

Siemens said it had injected 2.6bn euros into its pension funds in the fourth quarter and during October, to cover the plunge of equities held in its pensions portfolio.

It has now reduced the portfolios shortfall to 4.2bn euros.