WASHINGTON — The Federal Reserve gave its strongest signal yet that it would undertake a new effort this fall to strengthen the hobbling economic recovery.

Unless the economy improved significantly, “many members” of the Fed’s policymaking committee felt that additional stimulus would be needed “fairly soon,” according to an account of the group’s last meeting, which ended Aug. 1.

Policymakers didn’t specify which actions might be taken. But the meeting minutes, which were released Wednesday after the usual three-week lag, suggested that their preferred option was large-scale bond purchases known in Fed-talk as QE3, short for a third round of quantitative easing.

Some analysts said the new program, aimed at getting more dollars flowing into the economy, was likely to be announced at the conclusion of the Fed’s next two-day meeting, starting Sept. 12.

“Fed minutes suggest QE3 is a done deal,” said Paul Ashworth, an economist at Capital Economics, in the title of his research note.

Other economists didn’t go quite so far but agreed that the odds of further Fed action in the fall were now higher.

Since the Fed’s last meeting, the economy has shown somewhat stronger data, including a pickup in job growth and retail sales. Some said that could dissuade the Fed from pursuing more easing policies right away.

But the minutes revealed that it would take “substantial and sustainable strengthening in the pace of the economic recovery” for policymakers to hold off on new stimulus — and very few experts are predicting such improvement any time soon.

Martin Schwerdtfeger, senior economist at TD Bank, saw another reason for the Fed to act in September rather than later:

“The Fed might want to have more information before acting, which would augur for QE3 in October,” Schwerdtfeger wrote in a note to clients. “However, the proximity of the November presidential elections reduces the likelihood of such an outcome. Therefore, QE3 could come in September.”

The U.S. central bank previously launched two rounds of bond buying to drive down long-term interest rates and spur investment and lending, but some Fed officials and analysts have questioned whether a third effort would be beneficial, given that rates already are at very low levels.

Analysts such as Ashworth doubt that QE3 would have a meaningful and lasting economic effect. And Wall Street showed little enthusiasm Wednesday after the release of the minutes, with mixed results in the major indexes. The Dow Jones industrial average lost nearly 31 points, while the Nasdaq composite index and the Standard & Poor’s 500 index posted small gains.

The Fed minutes showed that policymakers also support another, more modest tool to bolster economic growth. Many would keep its benchmark short-term interest rate near zero beyond the end of 2014, its current qualified commitment.

don.lee@latimes.com