Minsait, which represents about half of Indra's business, would be worth 1.6 billion to 1.8 billion euros ($1.72 billion-$1.94 billion), El Confidencial said, adding Bain would make an offer for at least a 49% stake.
Indra's CEO Marc Murtra recently said the company was considering all options regarding Minsait to raise cash to finance its growth, El Confidencial said.
A spokesperson for Bain declined to comment. Cinven and Indra did not respond to requests for comment.
Indra's main shareholder is Spanish state holding company SEPI with a 25.2% stake, data from LSEG shows.
Indra's strategic relevance has increased since Russia's invasion of Ukraine as Spain has promised to boost its defence spending as required by NATO in the coming years.
($1 = 0.9282 euros)
(Reporting by Inti Landauro and Jakub Olesiuk)
