Landowners could triple the amount of revenue generated from having phone masts on their land.
The rental paid by companies is coming up for review and many landowners should be pressing for higher returns, according to chartered surveyors Fisher German.
Mark Newton, from the telecoms department of Fisher German, said many masts were being upgraded for the new 3G network and landowners should take advantage of that.
He said: "Early telecoms leases were often poorly drafted and are now coming to the end of their life. These leases can now be terminated and a new lease renegotiated with a higher rent, sometimes up to two or three times.
"The best increase we have managed to negotiate was 60 times the original rental."
There are also opportunities to re-negotiate where masts are being upgraded for the new 3G network, he said.
"Landowners need to be aware that they are in a strong position to push up the rent and improve terms, provided they have a good agent and solicitor working on their behalf and they are not restricted by their current lease," Mr Newton added.
Those in a good bargaining position are landowners with leases contracted out of sections 24 to 28 of Landlord and Tenant Act 1954, according to Fisher German.
"If this is the case, often the best course of action is to terminate the lease and ask the telecoms operator to leave the site. They may claim protection under the Communications Act 2003 but normally they will stay and agree more acceptable terms.
"Don't let yourself be bullied into taking a deal you later find out is a fairly poor one," Mr Newton added.