(Telecompaper) Hutchison Whampoa and VimpelCom are in advanced negotiations about a possible merger of their respective Italian mobile phone units, 3 Italia and Wind Telecomunicazioni, according to unnamed sources cited by the Financial Times. The companies have been holding on-off talks since December 2013, with Wind's net debt level and the exact split of ownership representing the main hurdles to a deal. However, an agreement is now close according to two of the sources, which suggested that Hutchison could end with a slightly larger share of the merged group. Another person familiar with the talks said Hutchison's share could be around 51 percent, although a decision could be weeks away and there is no certainty that a deal will be agreed. Wind is currently the third largest mobile operator in Italy behind Telecom Italia (TIM) and Vodafone, with 3 Italia coming in fourth. A merger would create a company with around 33 million customers and annual revenues of some EUR 7 billion. Wind recently said it expects to close the EUR 693 million sale of its mobile tower unit to Spanish infrastructure company Abertis by the end of the month, and that it would use the proceeds from the sale to reduce its net debt.