There were 2.5 million fewer underwater homes in the second quarter of 2013 compared with the first three months of the year, a decline of more than 25 percent, according to a new report from real estate data and analytics provider CoreLogic.

Approximately 7.1 million homes, or about 14.5 percent of all residential properties with a mortgage, remain underwater, according to CoreLogic. That’s down from 9.6 million, or 19.7 percent, in the first quarter.

According to CoreLogic, 11.5 percent of Massachusetts residential properties with a mortgage were underwater.

“In just the first half of 2013, almost three and a half million homeowners have returned to positive equity, but the pace of improvement will likely slow as price appreciation moderates in the second half,” Mark Fleming, chief economist for CoreLogic, said in a statement.

Of the 41.5 million residential properties with positive equity, 10.3 million have less than 20 percent equity. Such borrowers may be unable to refinance their homes, keeping them stuck with higher mortgage payments. At the end of the second quarter of 2013, 1.7 million residential properties had less than 5 percent equity and are still at risk of falling underwater should home prices fall.

The national aggregate value of negative equity was $428 billion at the end of the second quarter compared with $576 billion at the end of the first quarter of 2013, a decrease of more than $148 billion. This decrease was driven in large part by an improvement in home prices.

Nevada had the highest percentage of mortgaged properties in negative equity at 36.4 percent, followed by Florida (31.5 percent), Arizona (24.7 percent), Michigan (22.5 percent) and Georgia (20.7 percent). These top five states combined account for 34.9 percent of negative equity in the U.S.