Moody's Investors Service downgraded Starbucks Corp.'s senior unsecured rating by one notch to Baa1 from A3 Wednesday, after the company's decision to "materially" increase its debt load to support shareholder returns. Starbucks said Tuesday it is planning to return $25 billion to shareholders through 2020, up from a plan to return $15 billion in 2018. "The material increase in Starbuck's fixed shareholder return target will result in significantly higher debt levels and weaker credit metrics at a time of operating challenges" Moody's Senior Credit Officer Bill Fahy said in a statement. "We estimate that the additional debt needed to fund the proposed shareholder returns will result in leverage exceeding 2.8 times and retained cash flow to total debt of around 20%." The rating agency is also concerned that Starbucks may be reluctant to curtail shareholder returns if operating results fall short of estimates. Starbucks most active bonds, the 2.700% notes that mature in June of 2022, were last trading 19 basis points wider on the day at a yield spread of 62 basis points over comparable Treasurys. The company's shares were down 9.4%, while the S&P 500 was up 0.3%.