David Zinsner
Analyst · Bernstein Research
Thanks, Ali. The first quarter was a challenging quarter as we executed through weaker economic conditions and significant weakness in the portable consumer electronics sector. Nevertheless, our B2B markets combined to perform in line with our expectations and we repurchased $132 million of our shares in response to stock price volatility, which helped reduce our share count by approximately 1%.
Revenue in the first quarter totaled $769 million and diluted earnings per share was $0.56. Gross margin of 62.2% decreased 350 basis points from the prior quarter, primarily on higher inventory reserves and lower utilization rates. Inventory on a dollars basis decreased $7 million sequentially. And on a days basis was 128 days on lower sales.
Utilization rates in the first quarter were in the mid-50s and we are planning to increase utilization to the high 60s in the second quarter. Weeks of inventory and distribution were approximately 7.5 weeks, consistent with the prior quarter.
Operating expenses of approximately $265 million declined $27 million or 9% sequentially and were flat to the prior year as we continued to carefully manage expenses. Operating profit before tax of $214 million were 27.8% of sales, decreased from both the prior quarter and the year-ago period. Other expense was approximately $10 million as we raised $1.25 billion in 10- and 30-year notes. We expect our net interest expense for the remainder of fiscal 2016 to be approximately $15 million per quarter.
Our first quarter tax rate was approximately 13%, which we expect will be our tax rate for the remainder of fiscal 2016. Excluding special items, diluted earnings per share was $0.56, which was a decrease of 11% as compared to the prior year on higher inventory reserves and interest expense. Nevertheless, our strong financial model continued to generate solid cash flows, which we used to enhance shareholder returns. Excluding a onetime payment relating to the conversion of our Irish pension plan, over the past 12 months, ADI has generated free cash flow of $1 billion or 30% of sales, and we have returned $800 million to shareholders through dividends and share buybacks.
The first quarter was also a strong working capital quarter, during which free cash flow as a percent of revenue increased to 26%, up from 19% in the prior year, which is an increase of approximately 700 basis points. Capital additions in the first quarter were $23 million or 3% of revenue, and we are planning for capital additions in 2016 to be in the range of $130 million to $150 million.
In line with our capital allocation strategy, our Board of Directors approved a $0.02 increase in the quarterly dividend to $0.42 per share, which is payable on March 8, 2016. This dividend represents the 13th dividend increase in the last 12 years. At the current stock price, our dividend yield is approximately 3.2%. Our board also increased the authorization under our stock repurchase program to $1 billion as we plan to continue to repurchase our stock during periods of stock price volatility.
We ended the quarter with a cash and short-term investment balance of $3.8 billion, with approximately $1.2 billion available domestically. We had approximately $1.7 billion in debt outstanding, which resulted in a net cash position of $2.1 billion.
Now turning to our outlook for the second quarter, which with the exception of revenue expectations is on a non-GAAP basis and excludes special items that are outlined in today's release. While we are cautious about the macroeconomic environment, current order trends in the industrial, automotive and communications infrastructure markets suggest combined sequential revenue growth in these B2B markets to be in the mid- to high single digits in the second quarter.
In consumer, we're expecting another quarter of sequential weakness within the portable sector of this market. In the aggregate, we are planning for revenue in the second quarter to be in the range of minus 2% to plus 4% sequentially. Gross margins are expected to increase to approximately 65.5% in the second quarter on higher utilization, a more favorable mix and lower expected inventory reserves as compared to the first quarter. We estimate that operating expenses will be up slightly in the second quarter. And as a result, for operating margins to expand sequentially.
Based on these estimates and excluding any special items, diluted earnings per share are planned to be in the range of $0.58 to $0.66, which at the midpoint would represent an 11% sequential increase in EPS.
We are currently operating at the lower end of our financial leverage model range, and we are carefully managing production levels and operating expenses. As business conditions improve, we should drive better operating leverage. Overall, we estimate that we have approximately 800 basis points of operating leverage remaining in our financial model, based on our first quarter exit rates.
While near-term market headlines warrant caution, we believe our future prospects remain strong. We have been deepening and broadening our customer engagements while investing in our most critical technology vectors to support our long-term growth. And together with our operating model, these place ADI on a strong platform to achieve up to $5 in non-GAAP earnings by 2020.
And so now I'll turn the call back over to Ali.