BRUSSELS (Reuters) - Heineken NV (>> HEINEKEN), the world's third-largest brewer, announced better-than-expected earnings for the first half on Monday, helped by robust growth of its Tiger brand in Vietnam and rising beer sales in Mexico and parts of Europe.

The Dutch brewer, whose Heineken lager is Europe's top seller, increased profit on a like-for-like basis in all regions except Africa, but also saw a squeeze on U.S. margins. It said it expected faster sales growth in the second half of the year but maintained its full-year forecast for revenue growth, which will be slower than in 2014.

Heineken shares surged by as much as 4.5 percent to a three-month high after the results and were among the strongest performers in the FTSEurofirst 300 index <.FTEU3> of leading European stocks.

"It's a positive mixed bag. Some margin pressure in Africa and Americas, but central and eastern and western Europe good against tough comparables," said Trevor Stirling, beverage analyst at Bernstein Securities.

Stirling has an "outperform" rating on the stock, with potential for further emerging markets gains relative to larger rivals AB InBev (>> ANHEUSER-BUSCH INBEV) and SABMiller (>> SABMiller plc), whose emerging market progress, he said, was largely priced in.

Those rivals are also more exposed to China's slowing economy than Heineken, which is focused more on Southeast Asia.

Asia-Pacific was again Heineken's fastest growing market in the first half. It saw double-digit sales expansion in Vietnam, the region's third-largest beer market, driven by demand for Tiger beer, which Heineken has been promoting harder since acquiring full control of Asia Pacific Breweries in 2013.

With breweries from Mongolia to New Zealand, Asia-Pacific accounts for almost 20 percent of Heineken's operating profit.

Heineken also enjoyed solid sales in Mexico, but saw lower margins in the United States - where it imports Heineken and Mexican beers - due to higher marketing costs as it promoted cider and other new products.

In Europe, the Dutch group sold less beer, a year on from the football World Cup, but still persuaded its consumer to accept price hikes or shift to more expensive beer.

Higher profits in countries like Spain and Poland, were offset by lower earnings in Britain and Greece.

Africa was the group's weak spot, as a devaluation of the Nigerian naira currency led to inflation of over 9 percent, squeezing the brewer's margins. It also performed less well in unstable Democratic Republic of Congo and Egypt, where tourism dropped off.

Overall, consolidated operating profit before one-off items rose 3.4 percent on a like-for-like basis to 1.55 billion euros (1.09 billion pounds), above the average of 1.53 billion euros in a Reuters poll.

Heineken maintained its forecast of revenue growth, with volumes rising at a slower pace than in 2014 and weighted more to the second half. The company also targets annual improvements in operating margin of 40 basis points.

(Reporting By Philip Blenkinsop; Editing by Robert-Jan Bartunek and Susan Fenton)

By Philip Blenkinsop

Stocks treated in this article : HEINEKEN, ANHEUSER-BUSCH INBEV, SABMiller plc