NEW YORK (CNN/Money) - The merger and acquisition environment improved slightly in the first quarter. But investment bankers probably aren't popping champagne corks just yet.

According to research firm Dealogic, the total value of global deals in the first quarter was slightly higher than a year ago, at $300.4 billion compared to $292.7 billion. But the number of deals plunged 32 percent, with 6,208 deals announced last year and just 4,248 transactions in the first quarter of this year.

In addition, total deal value was 15 percent lower than the fourth quarter of 2002's total of $353.7 billion, further dampening hopes of a sustainable recovery in the M&A market. The figures are preliminary, since the first quarter doesn't end until March 31.

The pace of mergers continued to slow dramatically in the U.S. The value of the announced deals fell 21.3 percent, from $88.9 billion in last year's first quarter, to $70 billion this year. And the number of deals fell 27.9 percent.

Looking at individual sectors, telecom had the biggest increase in activity, with 220 deals totaling $61.8 billion, a 119 percent increase from the $28.3 billion's worth of mergers in last year's first quarter.

However, this increase is almost entirely due to one deal: Olivetti's $44.4 billion acquisition of Telecom Italia, which was the largest takeover this quarter. The biggest deal involving a U.S. company was Procter & Gamble's $6.9 billion bid for German hair-care company Wella.

The leading merger advisors were the usual suspects in the investment banking world. Goldman Sachs, Merrill Lynch, JP Morgan and Morgan Stanley were the top four advisors, ranked by global deal value. But Credit Suisse First Boston, which was #1 in the first quarter of 2002, fell to #7 even though it advised on the most deals.

The value of the 57 deals that CSFB was an advisor on was $28.2 billion. By way of comparison, Goldman advised on 49 deals that had a value of $103.5 billion. Deal value is crucial since advisory fees are typically based on the size of the transaction.