"Discussions are going on with a foreign carrier. We hope to conclude these negotiations expeditiously," a source said.
However, the sources refused to divulge any further details, saying shareholders would "get to know about it very soon".
When prodded, they said the potential investor in the media baron Kalanithi Maran-promoted airline was not from among the names doing the rounds in media.
While reacting to reports that the airline was in talks with Kuwait Airways to offload 25 per cent stake to it, SpiceJet had earlier this month said a few investors had evinced interest for equity purchase.
Some reports had also named Qatar Airways as showing interest in the airline.
"We reiterate that few investors have evinced interest in the company post the government allowing foreign direct investment by the foreign airlines in domestic carrier.
"It will be very premature to comment on the possibility of any fresh equity issuance to such interested parties or confirm/deny names of any such entity," the airline had said in a statement, terming the reports as "speculative."
The sources said keeping in view the recent developments, SpiceJet's promoters have asked the airline's chief executive Niel Mills to stay on till the negotiations with the potential investor are concluded.
Mills had resigned last week, but his resignation is yet to be accepted by the management. He is the third CEO of the Chennai-based private carrier in the past five years.
Mills' exit from SpiceJet comes a few months after its Chief Commercial Officer Harish Moideen Kutty resigned.
He had been hired by Maran for SpiceJet in 2010 from Gulf-based low cost carrier FlyDubai, months after the media baron had bought the airline from NRI promoter Bhulo Kansagra the same year.
In the last fiscal, SpiceJet posted a loss of Rs 191 crore. It has a market share of about 20 per cent compared with its main competitor IndiGo's 30 per cent.