UPDATE 1-Brazil's Oi posts 80 pct jump in profit in 2007

(Recasts; adds investment plans, details on profit)

SAO PAULO Feb 28 (Reuters) - Brazilian telecommunications group Oi Participacoes (TNLP3.SA)(TNE.N) said on Thursday its net profit jumped 48.6 percent in the fourth quarter and 80 percent in 2007, buoyed by strong growth in its mobile and broadband Internet businesses.

Oi, formerly known as Telemar, posted net income of 911 million reais ($545.5 million) for the fourth quarter, up from 613 million reais in the same period in 2006. For the whole of 2007, net profit surged to 2.36 billion reais from 1.31 billion reais the previous year.

The Rio de Janeiro-based company, which is in talks to acquire local rival Brasil Telecom Participacoes BRTP4.SA (BRP.N), also said it plans to invest 4 billion reais this year to expand its fixed-line and wireless networks.

About 33 percent of that amount, which does not include potential acquisitions, will be spent to boost Oi's presence in Sao Paulo, a lucrative market long dominated by Spanish rival Telefonica (TEF.MC).

Oi, which controls Brazil's largest fixed-line operator Oi Fixo (TMAR5.SA), said its fast-growing mobile and broadband services bolstered profits last year.

Oi Movel, the company's wireless unit, added 1.08 million clients in the fourth quarter, finishing the year with 15.98 million subscribers -- a 22 percent increase over 2006.

Oi's broadband Internet unit, Oi Velox, added 125,000 subscribers in the fourth quarter, lifting its user base by 9 percent from the previous quarter. In 2007, the number of broadband subscribers jumped 34.6 percent to 1.52 million.

Overall net revenue edged up 1.1 percent in the fourth quarter from the previous quarter, to 4.48 billion reais. In 2007, revenue rose 4.4 percent to 17.58 billion reais.

Earnings before interest, taxes, depreciation and amortization, a measure of cash flow known as EBITDA, rose to 1.55 billion reais in the fourth quarter from 1.5 billion reais in the same period in 2006.

($1=1.67 reais) (Reporting by Todd Benson, editing by Dave Zimmerman)