On pg 91 of the book
Messerschmitt Bf109A-E by Radinger/Schick
Performance:
@
0km - 460kph
1km - 480kph
2km - 500kph
3km - 520kph
4km - 540kph
5km - 555kph
6km - 555kph
7km - 550kph
Other data is also shown, ie Flight Limits, Range, Engine Performance at ground level and at altitude.
On the Inet,
Auszüge aus Flugzeugdatenblatt Bf 109 E-1, E-3 nach L.Dv.556/3
http://www.rolfwolf.de/daten/E4/Emil.html