* Net income rises to $536 million, or 71 cents per share

* Adjusted EPS beats estimates

* Debit volumes surpass credit volumes in the U.S.

* Shares slightly lower in after-hours trading (Adds CFO and analyst comments, U.S. debit volumes surpass credit volumes)

By Juan Lagorio

NEW YORK, April 29 (Reuters) - Visa Inc (V.N: Quote, Profile, Research) posted better-than-expected quarterly earnings on Wednesday as the world's largest credit card network increased prices, slashed expenses and consumers used debit cards more.

Net income rose 70 percent to $536 million, or 71 cents per diluted class A share, for the second quarter ended March 31, compared with a profit of $314 million, or 39 cents per diluted share, a year earlier.

On an adjusted basis, reflecting a normalized tax rate, restructuring and purchase amortizations, quarterly net income rose 38 percent to $553 million, or 73 cents per diluted class A common share. On that basis, analysts expected earnings of 64 cents per share, according to Reuters Estimates.

"What caught my attention most was the expense control they had. For instance, advertising falling from $210 million to $196 million. Their ability to cut costs in this environment is surprising," said Ken Crawford, senior portfolio manager at Argent Capital Management.