Vodafone and Tata Communications have been given three more weeks to make a formal offer for Cable and Wireless Worldwide.The previous deadline ran out today (March 29th). Vodafone originally said it was mulling a bid on February 11th, while Tata entered the fray at the beginning of March.The appeal for both companies is gaining access to the huge capacity offered by Cable and Wireless Worldwide's fibre network, the largest in the UK.There have been reports Tata has organised €2bn in financing ahead of a possible deal.The terms of today's announcement make clear that there can be no certainty of an offer from either party.Cable and Wireless Worldwide shares have gained 67% since Vodafone originally expressed an interest, at 10:41 today the stock was flat at 33.96pBS