On Wall Street, the rich may get still richer.

Investment bankers may see bonuses and other incentive pay rise 10 percent to 15 percent from elevated 2006 levels, while gains may be 15 percent for traders and 20 percent or more for workers in private equity, according to a study by Johnson Associates Inc., a prominent compensation consultant.

Financial services are benefiting from growth in international operations, proprietary trading and derivatives, and as low borrowing costs fuel record buyout activity.

"Many firms are building international businesses and seeing more and larger deals there, including in Asia and Europe," said Zanvi Patel, a vice president at New York-based Johnson Associates, in an interview. "Lenders are (also) benefiting from a healthy economy and record highs in some equity indexes.

"Companies have to balance their interest in boosting shareholder returns with a need to pay the producers who generate them."

Not all will benefit equally, the study said.

Incentives may rise 10 percent for workers who serve wealthy clients and 5 percent to 10 percent in both asset management and commercial banking, the study said. Retail banking employees may see gains of just 0 percent to 5 percent, as rising mortgage defaults crimp profit.

In 2006, incentive pay rose about 20 percent in investment banking; 12.5 percent to 15 percent in trading; 10 percent in asset management, commercial banking and high net worth; and 7.5 percent in retail banking, Johnson Associates said.

Bonuses for securities industry employees were projected last year to have risen 17 percent to a record $23.9 billion, according to a December estimate by former New York State Comptroller Alan Hevesi.

Incentives can comprise the bulk of compensation for top investment bankers and traders. Their overall pay regularly reaches seven figures and occasionally eight figures.

Several investment banking and trading specialists reported strong first-quarter results. Trading gains helped Goldman Sachs Group Inc. (GS) and Morgan Stanley post record profits and helped Citigroup's investment banking and trading unit increase profit 36 percent.

Merger activity also remains strong, including a roughly $90 billion battle for Dutch bank ABN AMRO Holding NV and buyouts led by Kohlberg Kravis Roberts & Co.'s planned $31.8 billion takeover of power company TXU Corp. (TXU).

Goldman in April closed a $20 billion buyout fund, while Blackstone Group LP, a private equity firm preparing to go public, said it has raised $19.6 billion for its latest fund.