Sales of previously owned homes edged up 0.6 percent in March, as buyers continued to respond to favorable mortgage interest rates, the National Association of Realtors reports.

The increase - which was seen as statistically insignificant - came on the heels of a massive 9.0 percent jump in sales last month, a leap most analysts said was due to bouoyed optimism as the Persian Gulf war drew to a close.But the March figure brought existing single-family home sales to a seasonally adjusted rate of 3.18 million and was cheering news to Realtors who had plunged into gloom when the January rate fell to a near-record low of 2.90 million.

Analysts now expect yearly sales to represent a slight increase over sales in 1990.

"That January number was incredibly low," said Daryl Delano at Cahners Economics in Newton, Mass. "We've come a ways from there, but on balance I think total resales will probably be only a little bit above where they were in 1990."

Besides the end of the war, observers said the stabilized housing market came as consumers responded to lower mortgage rates.

National rates for 30-year fixed-rate mortgages ranged between 9.40 percent and 9.59 percent during March, at least 0.5 percentage point below rates offered a year ago, according to the Federal Home Loan Mortgage Corp.

Sales also continued in the lower end of the market, reflecting improved housing af-fordability conditions for entry-level buyers, said NAR president Harley Rouda.