If anyone previously doubted whether Jon Gray had already become the true leader of Blackstone Group LP (NYSE: BX), the personnel changes that have unfolded over the past few weeks have completely erased such doubts.

Joe Baratta, the head of the firm's private equity business, will leave at the end of this year. Apart from Gray and Steve Schwarzman, Baratta was the only executive who also served as a member of the company's board of directors.

Earlier this month, Nadeem Meghji, the head of the real estate business, had already announced his departure. The business units led by these two executives together managed nearly 60% of Blackstone's $1.3 trillion in assets.

However, Blackstone has not arranged for new executives to replace them and grant them power of a similar scale. Instead, their responsibilities will be shared across a broader management team, accelerating the company's shift into a new era — one in which the age of a handful of dealmaking stars building massive investment empires and wielding enormous internal influence is gradually fading away.

Several senior executives have departed in succession in recent years, and the recent series of changes at the world's largest alternative asset manager reflects how Blackstone is moving away from its past model of being dominated by a few star investors and centered on large-scale M&A deals, pivoting instead toward building a "financial supermarket" with a broad business footprint that offers a full range of products and services to ordinary investors.

Gray, who serves as Blackstone's president, is the primary driving force behind this transformation, and he is regarded as the successor to take over as CEO from the 79-year-old founder Schwarzman.

Few executives embody Blackstone's old model better than Baratta. The billionaire is known for his meticulous work ethic and his demanding standards for the M&A team.

Schwarzman and Gray said in a memo sent to employees on Friday that the veteran, who has spent 28 years at the company, plans to retire at the end of the year. The two leaders highly praised the large-scale business expansion he drove during his tenure, while emphasizing that no single executive would succeed him and hold the same management authority across the entire private equity business.

"For many years, Joe has been committed to cultivating and empowering an experienced investment team, letting them separately oversee our various private equity investment strategies and funds," they wrote. "Given that we now have strong leadership teams across all of our private equity business segments, we do not intend to have someone replace Joe's role."

Although this change came somewhat suddenly, the transformation trend behind it has in fact been underway for many years. In 1985, Blackstone was founded by two entrepreneurs with $400,000; today, the company has grown into an alternative asset management giant with assets under management exceeding $1 trillion, and has joined the ranks of S&P 500 constituents with a market value of approximately $147 billion.

As the 56-year-old Gray leads the company to further expand into the retail market in pursuit of the growth that shareholders expect, Blackstone's corporate culture is also undergoing a shift.