NEW YORK (Reuters) - Alcoa Inc (>> Alcoa Inc.) gets a lot of attention at the start of every quarterly earnings season.

The aluminum producer's cache is burnished by its membership in the Dow Jones Industrial Average <.DJI> and its long history of being the first of the so-called blue chips to report its results each quarter.

However, Alcoa's earnings performance is so frequently divergent from key end markets like autos and construction, and its stock is such a notorious laggard, that some in the market question the company's status as a bellwether.

"I know accountants there that are like sweating blood to get this stuff out. They want to lead off, but for the longest time now, I don't know that they are a bellwether for the economy in general," said Kim Forrest, a senior equity research analyst at Fort Pitt Capital Group in Pittsburgh.

Take the stock's performance: Alcoa shares are down 3.9 percent for the year to date, while the Dow has gained 11.6 percent and the S&P 500 <.SPX> has added 9.7 percent.

Alcoa's stock hit a cyclical bottom in March 2009, around the same time the Dow and S&P 500. But while both market gauges have recently posted historical highs, Alcoa is 83 percent below its record high of $48.77 hit in mid-July 2007.

Alcoa is also by far the smallest stock in the Dow, with a market capitalization of $8.9 billion, less than a third of the next smallest, Travelers Cos (>> The Travelers Companies, Inc.) at $32 billion.

Arguably, its diminutive size could be grounds for removing Alcoa from the Dow, although the index manager is loathe to make frequent changes, and Alcoa has been in the index since 1959.

"We wouldn't be able to comment on potential changes to our indices. We consider that information to be market-moving, non-public," said Dave Guarino, spokesman for S&P Dow Jones Indices.

"We make changes to that index on as-needed basis, which generally occurs only after major corporate events like acquisitions, bankruptcies, dramatic shifts in business," he said.

The last component change was in September 2012, when it swapped in UnitedHealth Group (>> UnitedHealth Group Inc.) for Kraft Foods (>> Kraft Foods Group Inc) following Kraft's spinoff of its North America grocery business. In announcing the change, the index committee cited the diminished market cap of the restructured Kraft, now called Mondelez International (>> Mondelez International Inc), as well as its lower percentage of U.S.-based revenue. At the time, Mondelez's market cap exceeded $47 billion.

For its part, Alcoa does not promote itself as a bellwether for the entire stock market or economy. A company spokeswoman declined to comment.

Still, some analysts say Alcoa may be a valuable indicator of end markets that consume aluminum, such as car and plane manufacturing and home building.

"If we are making such a big deal out of the housing recovery, maybe people should be paying attention to Alcoa," said Doreen Mogavero, CEO of Mogavero, Lee & Co in New York.

In fact, Alcoa's profit beat market expectations handily when it reported first-quarter results after the stock market's close on Monday.

Moreover, it projected global growth this year across several end markets, including 9 to 10 percent growth in aerospace, 1 to 4 percent in automotive, and 4 to 5 percent in building and construction.

But even those projections belie its bellwether status. While its earnings per share rose, Alcoa's revenue declined nearly 3 percent from a year earlier, its fourth consecutive quarter of year-over-year sales drops.

By contrast, U.S. automotive output has risen every month since December 2010.

The story's not all that different when looking at the aerospace and construction sectors, either.

Aerospace equipment output has logged 18 straight months of year-over-year increases. Residential construction spending has risen year-over-year in every month since August 2011 and has been growing at a double-digit pace each month since last June.

Meanwhile, Alcoa sales of $5.8 billion not only declined, but fell short of analysts' projections of nearly $5.9 billion. Perhaps not surprising, Alcoa shares fell on Tuesday following the release of the results late Monday.

Alcoa's low share price of $8.39 at Monday's close earns it a meager 0.4 percent overall weighting in the Dow industrials. So even a big day for Alcoa barely moves the Dow's needle.

Alcoa has even less impact on the broader and market-cap weighted S&P, in which it registers a weighting of just 0.06 percent, making stocks like Air Products (>> Air Products & Chemicals, Inc.) and Intuit (>> Intuit Inc.) twice as important for the index. Starbucks (>> Starbucks Corporation) and Target (>> Target Corporation) each weigh about five times what Alcoa does. It would take almost 50 Alcoas to match Apple's (>> Apple Inc.) weight.

If nothing else, however, Alcoa appears to be a good proxy for the price of its main product: Aluminum. A simple correlation analysis over the past two years of daily activity produces a positive correlation coefficient of 0.935 - nearly one-for-one directional relationship.

(Reporting by Rodrigo Campos and Chuck Mikolajczak; Editing by Dan Burns, Bernard Orr)

By Rodrigo Campos and Chuck Mikolajczak