This is the tenth time we have received that honor in the past 12 years, and it is a testament to community awareness of the value of the quality care and experience patients receive at GNP member pharmacies.
Our philanthropic efforts have been recognized by DiversityInc, ranking us 8th in their annual 50 [list] in philanthropy rankings.
We finished the quarter with adjusted diluted earnings per share of $2.16, an increase of 17%, which was driven by the continued strong performance across AmerisourceBergen's businesses and also benefited from the one month contribution from the Alliance Healthcare acquisition.
Our consolidated revenue was $53.4 billion, up 18%, driven by revenue growth in both the Pharmaceutical Distribution Services segment and Other, which includes Alliance Healthcare and our Global Commercialization Services and Animal Health businesses.
Consolidated gross profit increased 32% to $1.6 billion, driven by increases in gross profit in each operating segment.
In the quarter, gross profit margin increased 33 basis points from the prior year quarter to 3.05%.
Regarding consolidated operating expenses, operating expenses were $996 million, up 38% year-over-year due to the addition of the Alliance Healthcare business and also includes the internal investments we are making across our business with a focus on continuing to offer innovative services and solutions to our partners.
Our operating income was $631 million, up 24% compared to the prior year quarter.
Operating income margin grew six basis points to 1.18% as a result of the contribution from the Alliance Healthcare acquisition and growth in higher-margin businesses.
The net interest expense was $51 million, up 36% due to debt related to the Alliance Healthcare acquisition.
Our effective income tax rate was 21%, up from 18.8% in the third quarter of fiscal 2020, which benefited from a discrete tax item.
Our diluted share count was 208.9 million shares, a 1.6% increase due to the dilution related to employee stock comp and the weighted average saving impact of the June issuance of two million shares delivered to Walgreens as a part of the Alliance Healthcare acquisition.
Our adjusted free cash flow was strong in our fiscal third quarter, bringing our year-to-date free cash flow number to $1.2 billion, while our cash balance was $2.6 billion.
Pharmaceutical Distribution Services segment revenue was $49.3 billion, up 13% for the quarter driven by increased sales of specialty products and solid performance broadly across our Pharmaceutical Distribution businesses.
Pharmaceutical Distribution Services segment's operating income increased about 13% to $484 million.
In the quarter, Other segment's revenue was $4.1 billion, up 128%, driven by the Alliance Healthcare acquisition and growth across the remaining operating segments.
Excluding the impact of Alliance Healthcare, Global Commercialization Services and Animal Health revenue was up 22%.
Other segment's operating income was $147 million, up 77% primarily due to the Alliance Healthcare acquisition and strong performance at both MWI and World Courier.
Excluding the impact of Alliance Healthcare, Global Commercialization Services and Animal Health operating income was up 21%, reflecting the solid fundamentals of the businesses.
Over 12 million families in the U.S. have gained pets since the pandemic began, and since pet owners view their pets as family members, the focus on health and wellbeing is a positive market trend for our MWI companion business.
Given the continued strong performance of AmerisourceBergen's businesses, we are again raising our earnings per share guidance from a range of $8.90 to $9.10, up to a range of $9.15 to $9.30, reflecting growth of 16% to 18% from the previous fiscal year.
Operating expenses are now expected to be approximately $3.9 billion due to the Alliance Healthcare acquisition.
We now expect operating income to be approximately $2.6 billion.
This rate also reflects our expectation for operating income in Other of approximately $610 million to $620 million.
Finally, turning to free cash flow, we have raised our free cash flow guidance to be approximately $1.7 billion, up from approximately $1.5 billion.
COVID therapy distribution contributes roughly $0.25 to our fiscal 2021 adjusted earnings per share guidance, and the benefit from that exclusivity is not expected to repeat in fiscal 2022.
Third, for the fourth quarter of fiscal 2021, we expect our weighted average shares to be almost 211 million shares due primarily to the fully planned impact of the two million shares of our stock delivered to Walgreens at the close of the Alliance Healthcare acquisition.
Our share count will continue to tick higher in 2022 due to normal employee stock comp-related solution and the fact that we have committed to prioritize paying down $2 billion in total debt over the next two years and [lower] shareholder purchases.

Summary:
We finished the quarter with adjusted diluted earnings per share of $2.16, an increase of 17%, which was driven by the continued strong performance across AmerisourceBergen's businesses and also benefited from the one month contribution from the Alliance Healthcare acquisition.
Our consolidated revenue was $53.4 billion, up 18%, driven by revenue growth in both the Pharmaceutical Distribution Services segment and Other, which includes Alliance Healthcare and our Global Commercialization Services and Animal Health businesses.
Given the continued strong performance of AmerisourceBergen's businesses, we are again raising our earnings per share guidance from a range of $8.90 to $9.10, up to a range of $9.15 to $9.30, reflecting growth of 16% to 18% from the previous fiscal year.
Finally, turning to free cash flow, we have raised our free cash flow guidance to be approximately $1.7 billion, up from approximately $1.5 billion.