A housing industry gauge suggests sales might have struck their low in August, while more data indicate softness in the manufacturing sector.

The National Association of Realtors this week released its pending sales index for existing homes; it rose at a seasonally adjusted annual rate of 4.3% to 110.1 from July’s 105.6.

The index was designed to try measuring which way the housing market is going in the future. A home sale is pending when the contract has been signed but the transaction has not closed. Pending sales typically close within one or two months of signing.

“Our sense is that home sales may have reached a low in August — the Pending Home Sales Index shows home sales should be fairly stable over the next two months, although a minor decline is possible,” the chief economist for the NAR, David Lereah, said.

The group last week reported sales of existing homes in America tumbled a fifth month in a row during August, dropping 0.5% to a 6.30 million annual rate.

“The substantial, 4.3% leap in the pending home sales index in August does not affect our gloomy housing view,” wrote the chief American economist at High Frequency Economics Ltd. in Valhalla, N.Y., Ian Shepherdson. “The index plunged 7.0% in July, far more than anyone expected, so the August number looks like a rebound to us. It is consistent with existing home sales about 6.15 (million); the August number was 6.30 (million).”

Weakness in the housing sector was unable to pull down overall American construction spending during August. Total spending increased by 0.3% to a seasonally adjusted annual rate of $1.201 trillion, the Commerce Department reported Monday. Residential construction spending fell by 1.4% to $625.62 billion.

Non-residential construction spending advanced by 2.3%, as outlays for manufacturing rose.

However, the Institute for Supply Management Monday reported its index of manufacturing activity for September fell to 52.9 from 54.5 in August. Pushing the index lower were the components of inventories, delivery times, and employment.

“These are all lagging indicators, while the leading indicators, orders and production, were little changed,” High Frequency’s Mr. Shepherdson wrote in a research note on the report. “This suggests there is no real momentum behind the dip in the headline yet and it is unlikely to fall further next month.”

Another recent, regional manufacturing indicator, the Federal Reserve Bank of Philadelphia’s business conditions index, fell to a reading of negative 0.4 in September, compared with 18.5 in August. Negative readings denote contraction. Economists had expected the index measuring mid-Atlantic manufacturing activity to register 15.

“The manufacturing sector continues on a trend of slowing growth in September,” said Norbert Ore, who directs the ISM survey released Monday. “While there was little change in new orders and production when compared to August, significant slowing took place in employment and inventories,” and “it’s apparent that manufacturing is losing momentum and feeling the effects of higher interest rates and a weaker housing market.”