correct tense

[Hanka]

Hi,

could you please help me? A company has web pages containing the following text:

For special tasks we also need partners we can rely on. Therefore we built / have built an adequate network mainly on the territory of Germany.

Which tense is correct here and why?

Thank you very much.

Hanka

[marseeprint]

we built - if the network was built some time ago and is not growing anymore

have built - if they started to build the network some time ago, and they kept building it untill now

there is another option too :

have been buiding - if they started to build the network some time ago, they still keep building it now, and they most likely will continue building it in the future.(it is in progress now)

I hope this helps (And I hope I am right, too )