NEW YORK (Bloomberg) — Lazard, the merger advisory firm run by Bruce Wasserstein, has hired former International Monetary Fund head Rodrigo de Rato to advise clients worldwide on corporate finance and help set the firm's strategy.

De Rato, 58, will start on February 1 as a senior managing director of investment banking, the New York-based firm said today in a statement. De Rato, who also served as Spain's finance minister, will be based in Madrid and London.

"He brings a wealth of economic knowledge and relationships in both the private and public sector," Steven Golub, Lazard's vice chairman, said in an interview. "That macroeconomic slant to the position will be very useful."

Lazard, which said in October that third-quarter earnings more than doubled to a record, has been making acquisitions and hiring senior bankers while bigger rivals including Citigroup shed jobs this year.

Lazard bought Australian mergers adviser Carnegie, Wylie & Co. in July and recruited Kazuki Kusaka from Lehman Brothers Holdings to advise on take-overs in Japan.

Ken Costa, a 31-year veteran of UBS AG and its predecessors, joined in October to run UK investment banking.

The firm ranks 13th this year among advisers on announced take-overs involving European companies, down from 11th in 2006, according to data compiled by Bloomberg.

"We continue to have a big backlog of announced transactions," Golub said. "The velocity of business is quite good in Europe."

De Rato was managing director of the IMF from June 2004 until October 31 this year. He was previously Spain's vice president for economic affairs and minister of economy, a position he'd held since 1996, and was a member of Spain's parliament from 1982 to 2004.

De Rato will be a "good addition" to Lazard's Spanish business, overseen by Pedro Pasquin, Golub said.

"We have a very good business in Spain and we think it will be stronger, but he's going to work on a global basis for us," Golub said.

Losses on securities linked to defaulting US home loans have driven down profit, and the share prices, of Lazard competitors such as Morgan Stanley, Merrill Lynch & Co. and Citigroup this year, spurring job reductions.

Lazard, which doesn't sell or trade mortgage-related securities, is almost unchanged in New York Stock Exchange composite trading for the year amid concern that a slowing economy may reduce demand for merger advice next year.