Retail sales perked up last month, rising nearly 1 percent after a disappointing March, according to figures released yesterday by the Department of Commerce.

Led by a strong surge in car sales, April's sales climbed to $112.2 billion -- 0.9 percent over March, when sales slumped by 0.7 percent. The actual March decline, however, was significantly less than the Commerce Department's original estimate; last month, the government had said March sales dropped 1.9 percent below February's level.

Economists, who had been awaiting the data to determine the health of the American economy, were somewhat heartened by the rebound in consumer spending.

"The numbers look quite encouraging," said John Hammond, director of consumer economics at Data Resources Inc. "It tells us that the consumer is still with us in the expansion and is not quite as fickle as the last couple of months of data had suggested. The real danger was that, after the huge decline, sales wouldn't rebound -- a sign that the consumer had abandoned the expansion."

White House spokesman Larry Speakes added, "The economy, as a whole, is still strong and healthy."

Yet some economists, while pleased with the increase, said that consumer spending remained sluggish. "Between March and April, there was very little net gain in retail sales," said the Commerce Department's chief economist, Robert Ortner. "It was a very modest improvement overall. We need a strong pickup in May and June if we are to have better growth in the second quarter than the first quarter."

Sandra Shaber, an economist with Chase Econometrics, added, "I don't think the numbers are particularly encouraging. Consumer demand is fairly anemic. What we have to look forward to for the rest of year is fairly sluggish growth."

The 1.6 percent increase in auto sales "is not sustainable. Much of the increase was due to a catch-up from a time when cars were in short supply," Shaber said. Additionally, she said, the 1.9 percent increase in department store sales does not offset the 2 percent sales drop in March.

"The good news today is that interest rates should decline," said David Berson, chief financial economist of Wharton Econometrics. "With the growth rate not that strong, you can expect the Federal Reserve to ease its policies to prevent a recession."

Overall, April retail sales, while only 0.9 percent above March, were 4.5 percent above a year ago. Excluding auto sales, retail sales increased 0.6 percent -- or 3.6 percent above April 1984.

Also yesterday, the Federal Reserve Board reported that Americans took on $8.34 billion more in installment debt than they paid off in March compared with a $9.04 billion advance registered in February.The February increase originally had been reported as a much higher $10.37 billion. At the end of March, outstanding installment debt totaled $476.98 billion, up 21 percent from a year ago.