The Italian champion's two best players have both threatened to leave the San Siro and have been linked to big spending Real Madrid, among other teams.
Moratti will meet the Spanish club's president Florentino Perez this week to discuss Ibrahimovic, Serie A' top scorer last season, according to reports in the Italian and Spanish media.
"As a fan I'd want them to stay, but as a president with a balance sheet to keep an eye on, I say that if they want to go, they can go. It would be counterproductive to keep them," Moratti said in an interview published in Monday's Il Giornale newspaper.
"I'd give them both a 50 percent chance of staying at Inter."
Moratti said he had already had talks with Barcelona about Ibrahimovic but added that the Catalans' president Joan Laporta was not "so motivated" about doing a deal.
He also confirmed that an Inter director had met Real Madrid last week to discuss Maicon, adding that Perez's lack of interest in signing defenders may help keep the Brazilian in Italy.
"Real Madrid have almost no interest in defenders, zero interest actually, which is fortunate because Maicon is the best full back in the world," he said.
Inter's chief executive Ernesto Paolillo said last week that a fair price for Ibrahimovic would be the 80 million pounds Real have bid to sign Cristiano Ronaldo from Manchester United.
The asking price for Maicon is 40 million euros, according to media reports.
