Fink is "trying to create a higher profile for himself as an evenhanded spokesman on corporate governance in general and on the financial industry in particular, and he does that on the sheer size of BlackRock," said Burton Greenwald, a mutual-fund consultant in Philadelphia.

Gross's visibility does have its downside. He missed a rally in U.S. Treasuries last year, which resulted in his Total Return Fund lagging behind 69 percent of peers and prompting the fund's first year of client withdrawals even as clients put money into other Pimco products. Gross wrote a letter to clients entitled "Mea Culpa," in which he called 2011 a "stinker."

Performance Not 'Terrific'

Performance at U.S. mutual funds managed by BlackRock may stand in the way of the firm's ambitions. In the three years ended Feb. 29, BlackRock's actively managed funds on an asset-weighted basis trailed 60 percent of their peers, according to data compiled by Morningstar. During the same period, Pimco beat 59 percent of its peers, Morningstar data show.

Over the past five years, BlackRock did better compared with many peers, beating 63 percent. Pimco's over that period outperformed 91 percent of peers, data from Morningstar show.

BlackRock said the comparison with Pimco is inaccurate given the broader, more diverse and global nature of BlackRock's business, and is ignoring BlackRock's institutional and non-US mutual fund businesses. BlackRock said that across all of its actively managed strategies globally 74 percent of assets outperformed benchmarks or peers over five years.

BlackRock has had "a lot of changes at the top, but what you haven't seen is this being synthesized into terrific performance," said Eric Jacobson, a senior analyst at Chicago-based Morningstar, referring to BlackRock.

'Pockets' Of Outperformance

The firm's first priority is delivering top performance for active funds, Fink said. At an event hosted by the UCLA Anderson School of Management and Bloomberg Television in November, Fink said he admires Pimco's consistent long-term track record and influence. Gross's Pimco Total Return returned an annual average of 8.3 percent in the five years through March 30, beating 98 percent of similarly managed funds, according to data compiled by Bloomberg. During the past 10 years, the fund gained 7 percent.

"I could give you pockets where we did really well consistently and areas not so well. However, the number one thing we have to be great at is performance in our alpha products," Fink, who has been chairman and CEO of the firm since co-founding it, said in the interview last month. Alpha products seek to beat the returns of market benchmarks.

BlackRock has work to do to improve its reputation among some institutional investors as well. It was rated No. 4 by pensions and No. 9 by nonprofits, compared with Pimco's No. 1 ranking for both, in terms of favorable impressions among prospective clients, according to a study released last month by Cogent Research that surveyed 650 pension and nonprofit investors with at least $20 million in assets.

BlackRock's Ascent