Every quarter I think that the run in shares of AmBev (ABV) might be over. After all the stock is up 42% in 2010 as of November 8.

But then the company does something to surprise me. And I decide that it’s worth staying on board.

This time, the company said on November 3, for the just completed third quarter, AmBev grew market share in Brazil.

Kind of amazing for AmBev. This isn’t only the leading brewer in Brazil; it’s by far the No. 1 brewer with 69.4% of the Brazilian market in the third quarter of 2009. It’s not easy to grow market share when you already have 69.4% of the market. There just aren’t a lot of low hanging fruit to grab.

But in this quarter, AmBev grew its share of the Brazilian market to 71.1%.

And that wasn’t the only piece of good news about the company’s markets. Across AmBev’s Latin American markets, and the company is the largest brewer in Latin America, economic growth is leading people to drink more beer and more expensive beer.

All this added up to a jump in net sales in Brazil of 20% in the quarter and a total increase in net sales of 11% for the company. Net income rose to 2.92 reais a share (“reais” is the plural of real) from 2 reais in the third quarter of 2009. That’s 46% growth in net income.

In its conference call AmBev said it expects to see full 2010 sales volume in Brazil up 10% from 2009. With sales up 14% in the first nine months of the year that seems like a safe prediction. The company noted that it had added 15% to production capacity in the last year by building new breweries.

Canada continued to lag the rest of the company. Net sales at the company’s Labatt unit dropped by 8.9% from the third quarter of 2009. Sales should pick up as the economy in Canada does, but progress has been slower than expected, the company said.

The company gets 60% of its sales from Brazil and the Brazilian economy is now projected to grow by 7.6%, the country’s central bank said on November 1.

The momentum from sales and earnings will get a boost in December when the company said it will split shares 5 for 1. I know stock splits logically should have no effect on investors—who will be getting five times the number of shares but each share will be worth only 1/5 as much—but it always does.

As of November 9, I’m raising my target price on these shares to $180 by July 2011 from $143 by March 2011.

Full disclosure: I don’t own shares of any of the companies mentioned in this post in my personal portfolio. The mutual fund I manage, Jubak Global Equity Fund (JUBAX), may or may not now own positions in any stock mentioned in this post. For a full list of the stocks in the fund as of the end of the most recent quarter, see the fund’s portfolio at http://jubakfund.com/about-the-fund/holdings/