Millicom officials have not commented on individual firms that are in the bidding process except to say that several firms are interested.
Media reports have suggested that Axiata, a unit of Malaysia Telekom, may be looking at Millicom assets.
The senior official from the UAE-based operator is currently visiting the tropical island meeting stakeholders, including the Telecommunications Regulatory Commission (TRC).
"I've told the representative from Etisalat that Sri Lanka is open for investments into new or existing operations," TRC director general, Priyantha Kariyapperuma said.
"With the war over in May, there is ample scope for investments into telecom services and infrastructure facilities, especially in the north and east," he said referring to the island's two regions that were cleared of Tamil Tiger separatists.
In 2006, Etisalat said they were looking for investments in mobile operations in Sri Lanka, Greece and Yemen. The firm had also shown interest in taking up stakes