As the deadline came and went for the submission of bids for top independent advertising agency Grey Global, the details of the offers were shrouded in mystery as the key players seemed unwilling to comment.

Britain's WPP Group reportedly offered cash and stock worth $1.3 billion (€1.1bn; £728m) for Grey's equity, but not its debt. WPP itself declined to comment.

Thus valuing the company at more than $900 a share, some believe the bid to be overpriced. Bob Willott, editor of industry newsletter Marketing Services Financial Intelligence cautioned that the offer required Grey's profits to more than double from the current level of 6.5%.

French advertising company Havas confirmed its board of directors supported a bid, thought to be worth around €1.5bn ($1.83bn; £1.02bn) financed by bank debt. This is despite doubts raised by main shareholder Vincent Bolloré, who's said to own a 5.1% stake.

Although WPP is the firm favourite for winning the hand of Grey -- largely due to Sir Martin Sorrell's intention not to remove Ed Meyer from his post as president/chairman/ceo -- Havas has more than a passing interest in the company.

The purchase of Grey would provide a welcome boost for its flagging US operations, and while some analysts believe it may be prepared to bid well over the market price, Havas declined to comment.

US private equity group Hellman & Friedman is also believed to have submitted a bid for Grey but, again, chose not to comment.

Assuming all will be shortly revealed, a decision on a sale may be expected within a week.

Data sourced from: Financial Times and BrandRepublic (UK); additional content by WARC staff