SAO PAULO, Dec 5 (Reuters) - Latin America's social and investment needs will outstrip its annual economic growth in coming years, the region's head strategist for BlackRock investment firm said on Tuesday, saying the region's economy could grow some 3% by 2026.

Axel Christensen, head regional strategist at the world's largest asset manager, said this estimate came from forecasts from multilateral organizations and investment banks and did not represent BlackRock's official guidance for the region.

"This is not enough growth to address the social demands and needs for investments," Christensen told journalists in Sao Paulo. "We are close to concluding that long-term growth for the region is lower than what we would expect."

A key factor would be how regional economies react when interest rates reach a "neither restrictive or stimulative" level, he added.

Brazil, Latin America's largest economy, narrowly avoided an economic contraction in the third quarter according to official data on Tuesday, growing 0.1% from the previous quarter and up 2% from the same period a year earlier.

Brazil's central bank began cutting rates in August. Its benchmark interest rate is now down 150 basis points at 12.25%.

Mexico, the region's No. 2 economy, saw its quarterly GDP grow 1.1% from the previous quarter and 3.3% from a year earlier, while rates have kept steady since March at 11.25% following a close to two-year tightening cycle.

Christensen nevertheless said that BlackRock had seen a series of investment opportunities in Latin America, notably in financial services and technology, while trade partnerships including talks between the European Union and Mercosur economic blocs were also encouraging. (Reporting by Patricia Vilas Boas; Writing and additional reporting by Andre Romani; Editing by Josie Kao)