Slow sharing over wifi

Hi all!

I tried today to transfer a 1.7 Gb file over wifi to a another mac (iMac running mountain lion) from my MacBookPro also running Mountain Lion

The result was disapointing as it took more than half an hour for that file despite the fact that the transmition ratio to my wifi router was above 140Mbps

Doing some calculations i found out that the transfer rate was at about 1Mbps...only

Any suggestions to fix things up ?

My router is a TP-Link TD-W8960N