SAN FRANCISCO (Reuters) - Coca-Cola Co (>> The Coca-Cola Co), PepsiCo (>> PepsiCo, Inc.) and other consumer-facing companies spending big bucks to advertise during Sunday's Super Bowl football extravaganza will be making a play for more market share to offset a slow economy and less overseas revenue.

In the year since the last Super Bowl, shares of companies selling everyday consumer products like food and cleaning supplies have outperformed most other sectors, partly because they are seen as relatively safe bets in world of growing macroeconomic worries.

But even that sector is vulnerable. Coca-Cola and PepsiCo are set to report December-quarter results on Tuesday and Thursday, respectively. Wall Street expects lower revenue and net income than a year ago for both, according to Thomson Reuters data.

They and other U.S. multinationals, including Super Bowl advertisers Anheuser-Busch InBev and Colgate-Palmolive (>> Colgate-Palmolive Company), have been clipped by a strong dollar that is cutting into revenues in Latin America and Asia. They also face lackluster demand in the United States, where money saved from low gasoline prices has failed to fuel a long-awaited lift in spending at stores.

Tepid economic growth has pushed companies to spend more on marketing in a bid to steal rivals' customers. That increase is reflected in pricing for Super Bowl ads, up 76 percent over the past decade, according to market research firm Kantar Media.

More than 100 million viewers in the United States and millions more around the world are expected to view Sunday's Super Bowl in Santa Clara, California.

Many familiar consumer brands are also struggling with the trend toward healthier foods and reduced loyalty to decades-old brands.

"Smaller niche brands are popular, they're cooler among the millennials and the incumbents are challenged," said Bernstein analyst Ali Dibadj. Larger brands "have to get the consumer to think the brand is worth something and that's why, in our opinion, they have to advertise more."

Coca-Cola and Pepsi are expanding their lineups of healthier drinks and snacks to appeal to changing tastes, while Anheuser-Busch is playing defense to growing numbers of small, local breweries catering to a thirst for premium, craft beers.

Exencial Wealth Advisors is waiting to see how successful Coca-Cola and PepsiCo are at rebalancing their businesses before investing in them, said David Yepez, an investment analyst at the firm, which oversees $1.4 billion.

The S&P consumer staples sector is expected to see first-quarter earnings fall 0.7 percent, pulled down by a 12.5-percent drop at Wal-Mart Stores (>> Wal-Mart Stores, Inc.), according to Thomson Reuters I/B/E/S. That compares to a 3.6 percent drop, on average, in earnings for S&P 500 companies.

Boston Beer Co (>> Boston Beer Co Inc), which sells Sam Adams and beer brands from regional breweries, is Morningstar analyst Adam Fleck's top stock pick. It trades around 23 times expected earnings, compared to 25 for Anheuser-Busch InBev, according to Thomson Reuters data. The company reports results Feb. 18.

"While SAM's long-term growth rate will inevitably decline, the company should grow its top line faster than the typical beverage company and also has quite a bit of room to increase its profitability over time," Fleck said.

(Reporting by Noel Randewich; Editing by Nick Zieminski)

By Noel Randewich