Sources in the agency said that Maxis will be asked to join the probe and respond to allegations made by former Aircel Chief C Sivasankaran.
Sivasankaran, who heads USD three billion conglomerate, Siva Group, with operations in realty, telecom, shipping and other areas, had alleged in his statement to the CBI that he was forced by Maran to sell his stake in Aircel to Maxis.
Sivasankaran had alleged that his applications for licences were rejected when Maran was the telecom minister in 2006, forcing him to sell his company to Maxis, whose owner is considered to be close to Maran and his brother Kalanidhi, who owns Sun TV.
Maran is alleged to have granted 14 licences to Dishnet Wireless (Aircel) during his tenure as the telecom minister.
CBI is looking into financial transactions of Sun TV and Maxis. Besides, it is also looking into various aspects of takeover of Aircel by Maxis group, the sources said.
Maxis has 74 per cent stake in Aircel which has presence in 23 telecom circles in different states.
The probe agency has already registered a preliminary enquiry on issues in 2G spectrum allocation between 2001-07 and is actively looking into matter.
The PE was registered against "unknown persons" following a Supreme Court directive to detect any alleged anomaly in the ''first-come-first-serve'' during the spectrum allocation between 2001-07.
Maran may be "examined" soon by CBI in connection with his alleged role in persuading Sivasankaran to sell his stake to a Malaysia-based group, the sources said.
They said Maran, who resigned as Textile Minister last month, will be asked to answer allegations levelled by Sivasankaran on spectrum policy changes made during his tenure as Telecom Minister.
They said CBI would soon wrap up the PE on the issue of spectrum allocation during the period 2001-07 which spans across three Telecom Ministers -- Pramod Mahajan, Arun Shourie and Dayanidhi Maran-- before registering aregular case.
Before registering a regular case, Maran will be given an opportinity to appear before CBI and give his statement, the sources said.
Arun Shourie, who had held the charge of Telecom ministry between 2003-04, recorded his statement with CBI on February 25 about allocation of telecom airwaves during his tenure but the agency has so far not found anything against him, they said.