Pimco's Bill Gross, manager of the world's largest bond fund, on Tuesday sought to reassure the firm's clients about the new leadership structure he has put in place since his heir apparent stunned the investment community last month by announcing his departure.

Gross called the collection of six new deputy chief investment officers a "significant improvement" from Pimco's previous structure, which concentrated nearly all investment strategy decision making onto the shoulders of Gross and Pimco Chief Executive Mohamed El-Erian.

El-Erian, who shared the chief investment officer title with Gross and long had been seen as his successor, will leave the Newport Beach, California-based firm in mid-March.

In the wake of El-Erian's announcement by Pimco in January, the investment firm has named Dan Ivascyn, Andrew Balls, Mark Kiesel, Virginie Maisonneuve, Scott Mather and Mihir Worah as deputy chief investment officers.

In a letter posted on Pimco's Web site, Gross said: "We will take turns chairing our daily meetings, which will allow for greater focus on certain sectors and regions. I also find that I often prefer to sit at the side of the table rather than at the head of it. I can contribute more effectively that way, learn more by listening, and it gives others the opportunity to lead."

Pimco observers considered the letter, which marked the second time Gross has publicly addressed the new management structure this month, as a response to clients who have grown edgy about the unexpected changes and Pimco's recent investment calls. Pimco's flagship Total Return Fund posted nine straight months of net outflows and notched its first negative return in 14 years in 2013.

"I think Pimco did this because they were caught totally off guard by Mohamed leaving," Morningstar senior research analyst Eric Jacobson said. "My impression is that they've been getting tremendous blowback from their clients, and now they are responding publicly."

Gross cited the depth of expertise across a broad array of assets and global regions of his deputy CIOs, even pointing out that Ivascyn was named Morningstar's Fixed Income Fund Manager of the Year for 2013 and Kiesel in 2012.

"We believe this new format, and the idea sharing it will facilitate, will be more responsive to market developments," Gross wrote. "It will be great!"

Gross advised clients and investors in his February investment letter on February 5 to "stick with Pimco." He also said: "Believe me when I say, we are a better team at this moment than we were before."

In January, investors yanked another $3.5 billion out of the Total Return Fund, adding to last year's record net outflows of $41.1 billion, according to Morningstar. The fund, with nearly $237 billion of assets, recorded a modest gain in January of 1.35 percent, but still lagged its benchmark, the Barclays U.S. Aggregate Index, which gained 1.48 percent. For all of 2013 it posted a negative total return of nearly 2 percent.

Gross said his new team are "experienced investors on the front lines of strategy and the pursuit of alpha, and their contributions can only deepen our understanding of the economy and markets and improve portfolio construction across PIMCO. Ultimately, their increased nimbleness within their channels and the added layers of intelligence they bring to the firm overall should translate into long-term value for our clients."