Apparently reports of Nokia giving away free turn by turn navigation software has had an effect on TomTom shares, causing them to fall some 3.7% reports an article over on Reuters.

The word is Nokia intends to hand out the free turn by turn navigation software to Nokia mobile phones in 74 countries, and TomTom fell 3.7% while Nokia rose 1.3%.

A trader at Keijser Capital, Geoffrey Leloux has said that personal navigation devices will come under further pressure and margins will suffer. He also said that it’s an important development for Nokia and is a good sales argument.

TomTom shares lost about a third of their value back in October when Google moved into free turn by turn navigation for their Android platform and was seen as a major threat to TomTom, so Nokia doing the same can only cause further grief for the Dutch navigation device maker.