America's biggest corporations spent less to buy back their stock at the end of 2011, the first time that's happened since the end of the financial crisis, Standard & Poor's said on Wednesday.

The reduced fourth-quarter buyback activity was deftly timed, as it came during a market rally that made shares more expensive for companies to repurchase. On average, shares climbed 11 percent.

Companies also had good timing in the third quarter, when buyback spending increased in a declining market that made stocks cheaper. Before that, repurchases had increased each quarter since the second quarter of 2009, just after the market hit bottom that March coming out of the financial crisis.

"Companies appear to have finally gotten it right," said Howard Silverblatt, an S&P Indices analyst.

Buybacks by companies in the Standard & Poor's 500 index totaled $91.5 billion in the final three months of 2011. That's down nearly 23 percent from last year's third quarter, when repurchases totaled $118.4 billion. That was nearly five times as large as the amount companies spent on buybacks during the second quarter of 2009.

While companies had good timing in reducing buybacks in the latest quarter, the decline means shareholders weren't rewarded as much from share repurchases as they were in previous quarters. Buybacks reward investors by increasing the value of remaining shares and lifting per-share earnings results. Shares are taken off the market, and earnings are divided among fewer shares.

Repurchases, as well as dividend increases, are attractive options now for companies to put their cash reserves to work. Reserves among S&P 500 companies recently topped a record $1 trillion. Most companies have been building up cash exiting the Great Recession, which officially ended in mid-2009.

Despite the fourth-quarter decline, 2011 was still a big year for buybacks. Companies in the S&P 500 increased their spending on buybacks by nearly 37 percent to $409 billion, from nearly $299 billion in 2010. The $118 billion spent in the third quarter was the biggest amount since buybacks hit a record $172 billion in the third quarter of 2007.

In the latest quarter, health care companies and energy companies were the only sectors to increase buybacks, compared with the previous quarter.

Among all companies, Exxon Mobil Corp. was the most active at buying back shares in the fourth quarter, with $5.4 billion in repurchases, down slightly from the company's $5.5 billion third-quarter total. The second-biggest buyer last quarter was biotech drug company Amgen Inc. with $5.3 billion in buybacks. No. 3 was chip-maker Intel Corp. with $4.2 billion.