NEW YORK (Reuters) - Bonuses at Wall Street firms will rise 15 percent this year despite ongoing pressure from investors, regulators and politicians about compensation levels, according to compensation-consulting firm Johnson Associates Inc.

The projected rise in pay would come after a 5 percent increase in 2012, which was considered "disappointing," Alan Johnson, head of the firm, said in a presentation to the Wall Street Compensation and Benefits Association that was released publicly on Friday.

Johnson expects chief executives to receive pay packages of $12 million to $25 million, even as investors question what they perceive as a misalignment between performance and pay.

"Overarching frustrations (and) questions remain unsolved," Johnson said. Among those questions are, "What is the appropriate balance between employees and shareholders?" and "Why can't incentives go to zero?" he added.

Johnson's projections - based on his work with banks, brokerages and asset management firms - are closely watched on Wall Street, particularly as compensation remains a hot-button issue for investors and taxpayers alike.

Since the onset of the global financial crisis in 2008 - and the ensuing backlash against bonuses paid to employees of bailed-out banks - the industry has made several changes to compensation plans. Base salaries have gone up, while more pay is deferred with clawback provisions to protect banks if deals that seem profitable at first eventually go awry.

A new "say on pay" measure that allows U.S. shareholders to vote on pay packages awarded to senior executives has also had an impact on executive compensation. Last year, Citigroup Inc shareholders embarrassed the bank by voting down former Chief Executive Vikram Pandit's pay. The bank has since made changes to its compensation practices for top executives.

The European Union and Switzerland have also approved compensation caps that limit banker pay to a certain portion of base salary.

Yet those provisions have failed to prevent banks from paying out higher bonuses, even in years when performance suffers. Credit Suisse Group AG gave its CEO a big raise last year, even though its profits fell.

The median bank or asset manager paid out a greater portion of revenue to employees in 2012 than they did the previous year, Johnson Associates said. That rise comes despite staff cuts last year at most major financial-services firms.

Payouts of deferred compensation from prior years skews those figures higher, according to the presentation. It is difficult to tell on a firm-specific basis how much of a compensation expense pertains to prior-year awards, because most firms do not disclose those figures.

The lack of transparency about how compensation and performance are linked will continue to hurt banks this year, Johnson said.

(Editing by Bob Burgdorfer)