Nico's agent is said to have settled contract terms with Barca sports director Deco and the Blaugrana now plan to pay his €58m buyout clause.
Barca's public pursuit has angered Athletic directors, with many expressing their disappointment with the Catalans' tactics.
But Laporta insists: "We don't have a bad relationship with Athletic . In recent years there have been a series of misunderstandings and incidents, but I don't think you can say we have a bad relationship for this reason.
"We're clubs with a very long history. I don't understand the reactions they're having. With all due respect, everyone should mind their own business. I don't understand why they're going to talk about Barça to LaLiga ; I don't think it's appropriate. They'll know what they're doing."
We'll sign who we want to sign
Asked directly about Nico, Laporta also told La Llotja del 125: "I'm only referring to market opportunities and ensuring that it's in accordance with what the coach wants.
"We're working to be within the 1:1 rule, which we already were in the winter transfer window. All the steps have been taken to be able to sign normally, so as not to be financially intervened.
"I understand that right now we can sign normally, complying with certain parameters, which is what we're doing. We'll sign what we want to sign and register them."