UPDATE 2-Telefonica ups bid for Brazil GVT; Vivendi silent

* Telefonica ups GVT offer by 5.2 pct to 50.50 reais/share

* GVT shares gained 1.4 pct to 51.70 reais, above offer

* Vivendi, rival in pursuit of GVT, remains silent (Adds advisers, takeover financing package, share prices)

By Guillermo Parra-Bernal

SAO PAULO, Nov 4 (Reuters) - Spanish telecommunications company Telefonica (TEF.MC: Quote, Profile, Research) raised its offer for Brazilian rival GVT (GVTT3.SA: Quote, Profile, Research) on Wednesday by 5.2 percent, seeking to trump a potential counteroffer by French media group Vivendi (VIV.PA: Quote, Profile, Research) and seal a deal by the end of the month.

Management at Telefonica's Telesp (TLPP4.SA: Quote, Profile, Research) unit raised the offer in order to "ensure the success of its bid and to reinforce its intention" to buy GVT, according to a regulatory filing. Under the new terms, the bid was upped to 50.50 reais a share, valuing the deal at $3.9 billion, from 48 reais a share, or $3.7 billion, previously.

The move sent GVT shares as much as 1.4 percent higher to 51.70 reais -- above the improved Telefonica offer. They later backtracked slightly and were trading 1.2 percent ahead at 51.60 reais.

The decision to raise the bid was based on GVT's "encouraging" third-quarter results, the filing said. GVT, which is based in the southern Brazilian city of Curitiba, reported net income of 57.2 million reais ($33 million) for the quarter, compared with a loss of 14.8 million reais a year earlier.

Faced with eroding margins and saddled with fines for poor service in Sao Paulo state, Telefonica needs GVT to revive bottom-line growth. The decision to boost the offer highlights the company's willingness to grab GVT and trump any additional offer by Vivendi or any other suitor, analysts said. [ID:nN30326429]