SAO PAULO, Nov 12 (Reuters) - Brazilian stocks seesawed in early trading on Thursday, as investors cashed in on recent gains made on the back of ongoing investor interest for Brazilian assets.

The benchmark Bovespa index .BVSP dipped 0.21 percent to 66,289.26 in morning trading despite a brief foray into positive territory. The index has gained over the past three sessions.

Brazil's currency, the real (BRBY: Quote, Profile, Research), weakened 0.17 percent to 1.725 per dollar as the greenback strengthened against a basket of major currencies .DXY.

"It's a round of profit-taking," said Ernesto Leme, a partner at Claritas Wealth Management.

But whether the index's fall would last to the end of the day was harder to predict, he said. The index slid much of Tuesday and Wednesday as well, but ultimately rallied late in those days and squeaked out gains.

"There's still a lot of interest from foreign investors," he said.

Commodities were also lower, pressured by the stronger dollar, with the 19-commodity Reuters-Jefferies index .CRB slipping 0.44 percent.

The Bovespa index includes a number of companies tied to the trade of raw materials, and the decline in commodities hurt mining company Vale and some Brazilian steelmakers, which were falling early on Thursday.

Vale (VALE5.SA: Quote, Profile, Research), the world's largest iron ore producer, led losses, moving down 0.73 percent to 42.02 reais.