By Nick Timiraos

The number of homes listed for sale ticked up slightly in many metropolitan areas last month as the spring sales season begins in earnest.

The supply of homes available for sale in more than 140 metropolitan areas at the end of April was up 1.1% from a month earlier, according to figures compiled by Realtor.com.

Nationally, inventories typically rise in April from March as the busy shopping season gets underway. Over the last 28 years, the average increase in April has been around 5%, according to research firm Zelman Associates.

Overall, for-sale inventories were down 8.25% from one year ago, when tax credits were bringing more properties to the market and there were fewer roadblocks in the foreclosure process. Inventory counts were down from one year ago in 128 of the 146 markets reported by Realtor.com, but they were up from March in 100 markets.

Inventory levels have been suppressed in recent months by banks that have had to retool their foreclosure processes in light of widespread document-handling abuses that surfaced last fall. More than two million homes are in some stage of foreclosure, and millions more are behind on their payments and at risk of foreclosure.

Compared with March, the largest inventory increases came in Boston (12%), New Haven, Conn., (9.3%) and Washington, D.C., (8.2%). Listings were down most sharply in three Florida markets: Miami (-12.7%), Orlando (-10.8%) and Fort Lauderdale (-10.6%).

Compared with one year ago, Las Vegas posted an 8.3% increase, while New York City was up 5.8%. Orlando and Miami saw the biggest decline in listings, down 34% and 30% from last April, respectively.