By Lucia Mutikani

WASHINGTON (Reuters) - Wholesale inventories rose solidly in February as petroleum recorded the biggest increase in a year, prompting analysts to raise their estimates for first-quarter economic growth.

Total wholesale inventories increased 0.9 percent to a record $478.9 billion, the Commerce Department said on Tuesday, after an upwardly revised 0.6 percent rise in January.

Inventories are a key component of gross domestic product changes and the rise in wholesale stocks in February and upward revisions to the prior month's data, saw economists, including those at Goldman Sachs and Barclays, lift their forecasts for first-quarter gross domestic product growth.

"The result implies more inventory building in the first quarter than we had previously assumed," Goldman Sachs economists said in a research note.

"We therefore raised our tracking estimate of Q1 GDP growth by two tenths to 2.3 percent annualized. We now expect that inventory accumulation added a small amount to overall GDP growth during the quarter."

Economists polled by Reuters had expected stocks of unsold goods at U.S. wholesalers to rise 0.5 percent in February after a previously reported 0.4 percent gain in January.

Inventories accounted for much of the economy's annual 3 percent growth pace in the fourth quarter.

Economists had feared that businesses had little appetite to continue adding to stocks, holding back GDP growth in the first three months of 2012.

Data next week on overall business inventories for February could shed more light on how much of a boost restocking will be to first-quarter GDP. First quarter GDP growth estimates now range between 2.2 percent and 2.6 percent.

The value of petroleum stocks jumped 5.6 percent in February, the largest gain since February 2011, after rising 2.8 percent in January.

Automobile inventories fell 0.9 percent in February, reflecting strong demand for motor vehicles, after rising 0.6 percent in January.

Even though growth is expected to have slowed in the last quarter, there are no signs of an unwanted piling up of goods, with sales at wholesalers rising broadly in February.

Overall sales rebounded 1.2 percent after being flat in January. That was well above economists' expectations for a 0.7 percent increase.

Sales at wholesalers in February were mostly broad-based. Auto sales gained 0.2 percent. Petroleum increased 3.9 percent. At February's sales pace it will take 1.17 months to clear shelves, a rate unchanged from January.

The inventory-to-sales ratio remains above an all-time low of 1.14 months touched in June 2008.

"The inventory-to-sales ratio has been flat at 1.17 for five consecutive months, an encouraging sign that recent strength in inventory accumulation is reflective of an improving outlook for demand, rather than lackluster sales," said Peter Newland, a senior economist at Barclays.

(Reporting By Lucia Mutikani; Editing by Neil Stempleman and Andrew Hay)