AdvancedAdvT is the vehicle of software entrepreneur Vin Murria, M&C's deputy chairman and biggest investor.

AdvancedAdvT submitted a revised bid to the board of M&C Saatchi late last week, which included roughly 40 pence-a-share in cash, a shift from the initial all-share offer, Sky News said, citing City sources.

M&C could not immediately be reached for comment. AdvancedAdvT declined to comment.

The advertising group had said on Jan. 7 that it did not see much merit in a possible all-share takeover instigated by its biggest investor.

Shares in M&C fell early on Jan. 7, when AdvancedAdvT said a takeover proposal would be in shares, and tumbled again when M&C gave its response later in the day to close down more than 12%.

Murria owns 13% of AdvancedAdvT, in which private equity group Marwyn is the biggest shareholder. She also owns 12.5% of M&C directly, while AdvancedAdvT owns another 9.8%.

(Reporting by Vishal Vivek in BengaluruEditing by Gareth Jones and Susan Fenton)