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SAO PAULO, Oct 29 (Reuters) - Brazilian stocks posted their biggest one-day jump since May 4 on Thursday, regaining much of the ground lost in a two-session slump after new data showed the United States returned to growth in the third quarter.

The benchmark Bovespa index .BVSP surged 5.9 percent to 63,720.58, partially wiping out the almost 7 percent in cumulative losses over the previous two sessions.

The news of the U.S expansion moved markets around the world, reassuring investors and whetting their appetite for riskier emerging market assets.

Brazil's currency, the real (BRBY: Quote, Profile, Research), strengthened 1.4 percent on the back of that risk appetite to 1.731 per dollar, its biggest one-day advance since Aug. 3.

Data showed on Thursday that gross domestic product in the United States expanded 3.5 percent last quarter, the fastest pace since the third quarter of 2007 and above economists' forecasts. [ID:nN28314202]

Because the United States is the world's largest economy, its health influences financial decisions worldwide.

"This confirms more optimistic scenarios," said Pedro Paulo Silveira, chief economist with Gradual Investimentos. "This takes some of the air out of the pessimistic views."

Brazil's economy exited recession in the second quarter, ahead of many more developed economies, as politicians here have been quick to note.