Xerox Corp., the photocopier pioneer, issued $500 million of bonds a day after its credit rating was boosted by Standard & Poor’s.

The company sold 2.75 percent debt due March 2019 to yield 137.5 basis points more than similar-maturity Treasurys, according to data compiled by Bloomberg. The sale was increased from an original $300 million, according to a person with knowledge of the transaction who asked not to be identified, citing lack of authorization to speak publicly.

S&P raised Xerox one level to BBB from the lowest investment-grade ranking of BBB-, citing a change in the grader’s ratios and adjustments that improved a measure of the company’s cash flow and leverage, the ratings company said yesterday in a statement. The bonds are expected to be rated an equivalent Baa2 by Moody’s Investors Service, the person said.

Xerox last sold debt in March 2012, issuing $1.1 billion that included $500 million of 2.95 percent debentures due March 2017 at a relative yield of 210 basis points, Bloomberg data show. The bonds traded at 103.2 cents on the dollar to yield 1.96 percent on Oct. 31, according to Trace, the bond-price reporting system of the Financial Industry Regulatory Authority.

Bank of America Corp., Goldman Sachs Group Inc. and JPMorgan Chase & Co. managed the sale for the Norwalk, Connecticut-based company, Bloomberg data show. Proceeds will be used for general corporate purposes.