By David Randall

NEW YORK (Reuters) - Some tech-heavy U.S. fund managers have turned to the once-stodgy payments sector as an alternative to so-called FANG stocks as high-flyers like Facebook Inc (FB.O) and Google parent Alphabet Inc (GOOGL.O) falter.

Companies underpinning online shopping and mobile payments, such as Visa Inc (V.N), Mastercard Inc (MA.N) and PayPal Holdings Inc (PYPL.O), offer above-average growth at a more reasonable valuation than FANGs and held onto more gains during recent market volatility, fund managers said.

Visa, for instance, is down 2.9 percent over the last 3 months, compared with a 30 percent plunge in Facebook and Alphabet's 13.5 percent decline. The broad S&P 500 has fallen approximately 4.8 percent over the same time.

"Right now we're certainly looking at a test of the past (market) leadership and some of these FANG stocks have gotten ahead of themselves," said Tom Plumb, portfolio manager of the Plumb Equity fund, who recently added a position in Square Inc (SQ.N).

"We're looking with companies that have high recurring revenue and high growth, and not a lot of companies are in a better spot than the payments space."

Fund managers from firms including Villere & Co, Plumb Funds, and Ave Maria Mutual Funds said they have moved out of the FANG group of Facebook, Amazon.com Inc (AMZN.O), Netflix Inc (NFLX.O) and Alphabet that had led the market this year during the recent volatility because valuations did not appear sustainable.

The fund managers said they see the payments sector as a way to tap into growth in e-commerce and mobile computing at a more attractive multiple than FANGs.

Amazon trades at a trailing price-to-earnings ratio of 160.6, for example, while Visa trades at a P/E of 38.3.

"You're getting a lot of the same disruption but at a fraction of the price," said Lamar Villere, a portfolio manager at New Orleans-based Villere & Co, who has positions in Visa and transaction processing company Euronet Worldwide Inc (EEFT.O). Euronet shares are up 33.9 percent for the year.

Visa and MasterCard in particular are a way to tap into the growth of e-commerce without directly owning online sellers like Amazon, said Brian Milligan, portfolio manager of the Ave Maria Growth fund.

Online sales are expected to make up 17 percent of all U.S. retail sales by 2022, up from 12.7 percent in 2017, according to Forrester Research.

"They are benefiting from the same secular growth as Amazon, but they are a duopoly," Milligan said.

Investors have also been moving into payment-focused exchange-traded funds.