MILAN, Oct 14 (Reuters) - Telecom Italia (TIM) was unable to take a decision on a key network deal on Friday as representatives of top investor Vivendi did not attend a special board meeting in a clash with the chairman of the former phone monopoly.

Italian state-lender Cassa Depositi e Prestiti (CDP), infrastructure fund Macquarie and Open Fiber have asked for more time to negotiate a deal to buy TIM's network assets, seeking to delay an initial deadline for a binding agreement by the end of this month.

TIM held a special board meeting on Friday to discuss the request but was not able to decide in the absence of Vivendi's representatives, two sources familiar with the matter said.

A person close to Vivendi said the French media company's representatives on TIM's board had informed TIM Chairman Salvatore Rossi in advance of prior engagements that made it impossible for them to attend Friday's meeting.

The person added Arnaud de Puyfontaine and Frank Cadoret were "surprised" the board was still convened.

Other sources have previously told Reuters Vivendi was piling pressure on TIM to replace Rossi, a former Bank of Italy top official, with veteran manager Massimo Sarmi, the head of Italy's telecoms lobby group.

TURNAROUND PLAN

The grid sale is a key plank of the strategy set by TIM Chief Executive Pietro Labriola to turn around the debt-laden group whose shares hit a record low on Thursday.

TIM is now expected to convene another board meeting to discuss the deal postponement.

The potential multi-billion euro bid is part of a long-held plan to combine TIM's fixed network assets with those of smaller rival Open Fiber to create a single national network operator under CDP's control.

Treasury-owned CDP, which holds a 10% stake in TIM, controls Open Fiber.

The initial timeline for a non-binding bid has been subject to multiple delays and has been further complicated by a snap national election last month.

Divergences on valuations have also been a stumbling block, with Vivendi seeking 31 billion euros to back a deal, at least 10 billion above CDP's valuation, sources have said.

Sponsored by the outgoing government of Mario Draghi, CDP's plans to create a single broadband network champion will now have to be reviewed by a new right-wing government which is due to be installed later this month.

The French group is ready to "build a positive dialogue and collaborate" with the new executive set to take office in Rome this month, the person close to Vivendi said. (Reporting by Elvira Pollina, editing by Gianluca Semeraro and Keith Weir)