A record number of homes entered the foreclosure process in the second quarter, and housing market problems have put mounting strain on prime loans, according to data released yesterday by the Mortgage Bankers Association.

This marked the third straight quarter of a record number of homes entering foreclosure. Pressure remained the most severe on subprime adjustable-rate mortgages, as 18 states reported at least 19% of these loans were delinquent. More than 26% of the borrowers with subprime ARMs in Mississippi and West Virginia were delinquent, the MBA said.

The data don’t take into account the recent credit crunch experienced by the mortgage finance industry in July and August. The chief economist of the MBA, Doug Duncan, said this would continue to put stress on foreclosure and delinquency data.

“We do not yet believe we have seen the peak, though there is some reason to believe that that will be in the next two to four quarters,” Mr. Duncan said in a call with reporters.

Mr. Duncan said liquidity pressures could push the total inventory of homes in foreclosure to a record high in that timeframe.

“Prime, jumbo adjustable-rate mortgages are not being purchased as collateral for securities by investors,” he said. “They have simply left the marketplace.”

On a seasonally adjusted basis, 0.65% of homes entered the foreclosure process in the second quarter, shattering the 0.58% record set in the first quarter. The second-quarter foreclosure starts were 44% higher than in the second quarter of 2006.

The rise in foreclosure starts comes despite intensified efforts by regulators, lawmakers, and lenders to stem the tide of delinquencies.