Johnson & Johnson’s $25.4 billion takeover of Guidant Corporation and 71 other acquisitions announced yesterday made this quarter the busiest for mergers in more than four years.

Companies have spent $575 billion on takeovers since the start of October, the most since the second quarter of 2000, when $761 billion of acquisitions were made. At least 72 purchases worth $59 billion were announced yesterday.

Mergers are picking up as stock markets recover and global economic growth gathers pace. The Standard & Poor’s 500 Index is the highest since August 3, 2001. World economic growth is projected to expand 5% this year, the fastest in three decades, the International Monetary Fund forecast in September.

“There’s no doubt that as the stability of capital markets persists, the recovery in the M&A market is gathering momentum,” said Paulo Pereira, head of European mergers and acquisitions at Morgan Stanley, the no. 4 adviser on takeovers this year.

Companies have announced $122 billion in acquisitions this week, the most since the five-days that started on October 25. Sprint Corporation’s $41 billion purchase of Nextel Communications, announced on Wednesday, was the biggest.

Johnson & Johnson, the world’s biggest maker of medical devices, yesterday agreed to buy Indianapolisbased Guidant, adding electrical devices for treating heart diseases its to healthcare products. Symantec Corporation, the world’s largest maker of computer antivirus programs, agreed to buy Veritas Software Corporation for $13.5 billion in the second-biggest software-company merger. Noble Energy Inc. agreed to buy Patina Oil & Gas Corp. for $2.76 billion.

United Technologies Corp. yesterday announced a plan to buy Kidde Plc of Britain for $2.8 billion in cash to add fire-protection products to its Chubb burglar alarms and Otis elevators.

Rising stock markets have boosted management confidence to do deals, said a takeover specialist at Cass Business School of the City University in London, Scott Moeller. The S&P 500 has gained 13% since this year’s low on August 12.

“People are talking about markets going up, and companies are confident about their share value to do the deals,” Mr. Moeller said in a telephone interview. “Companies still have their strategic imperatives that are easier achieved through acquisitions.”

Citigroup Global Markets’ chief American strategist, Tobias Levkovich, on December 6 lifted his 2005 forecast for the Standard & Poor’s 500 Index, citing the falling dollar, lower energy prices, and increased earnings estimates. Mr. Levkovich said the S&P 500 may rise to 1,300 next year, up from his previous forecast of 1225. That’s a 9.1% gain from the December 3 close of 1,191.17.

Morgan Stanley, JPMorgan Chase & Company, and Goldman Sachs Group Inc., all based in New York, may share as much as $46.7 million in fees for negotiating Johnson & Johnson’s takeover of Guidant. JPMorgan and Morgan Stanley probably shared about $28.8 million for advising Guidant, while Goldman may have earned $18 million for advising John son & Johnson.

Goldman Sachs ranks top in advising on acquisitions this year, with 292 deals worth $560 billion, followed by JPMorgan and Citigroup. Sullivan & Cromwell is the no. 1 legal adviser, with 134 transactions worth $380 billion.

In Europe this quarter, 1,499 takeovers have been announced worth $299 billion. American companies have made 1,950 acquisitions worth $263 billion. Excluding the $80 billion combination of Royal Dutch/Shell Group’s British and Dutch parent companies, in which no money or control changed hands,American mergers outpaced Europe.

“Previously anticipated transactions, like Sprint, come to fruition as threshold events are crossed, such as the U.S. elections,” said Mr. Pereira, 44. “There is also somewhat of a rush to get deals announced before the end of the year.”

Deutsche Boerse AG, operator of the Frankfurt Stock Exchange, on December 13 made a second attempt in five years to buy London Stock Exchange Plc, offering $2.6 billion. LSE rejected the bid and agreed to hold talks with Deutsche Boerse. PeopleSoft the same day capitulated to Oracle, accepting a $10.3 billion takeover offer to end an 18-month battle.

“The outlook on global economic growth is positive,and this always helps boost mergers and acquisitions,” said Andrea Fuccio, a fund manager at a unit of Banca Popolare di Verona e Novara Scrl in Milan that oversees $9 billion. “M &A activity has been picking up this quarter and it will continue next year.”

The world economy may expand more than 4% in 2005, and any drop in oil prices will underpin growth, said International Monetary Fund chief economist, Raghuram Rajan.

“There’s a lot of pent-up activity and enthusiasm,” said Stephen Barrett, a director of KPMG’s corporate finance unit in London. “We’ll see a strong 2005.”