Standard & Poor's lowered its outlook for beverage company Constellation Brands Thursday, saying its credit measures won't improve as much as previously expected.

The ratings agency revised its outlook for Constellation Brands to "stable" from "positive" but affirmed its "BB" rating on the company.

Analyst Jean Stout wrote that Constellation Brands net sales and earnings before interest, taxes, depreciation and amortization were lower than expected in the most recent quarter.

The announced repurchase of $300 million of shares may also slow debt reduction efforts in fiscal 2011 even though the company trimmed its debt by $600 million in the 2010 fiscal year, Stout wrote.