U.S. stocks rose on Friday as a brokerage upgrade of Procter & Gamble

lifted shares of consumer staples companies, putting the market on track for a second week of gains.

Citigroup said Procter, which makes Tide detergent and Pampers disposable diapers, is poised to win market share through aggressive pricing.

Procter's shares gained 3.3 percent to $57.38, while the S&P consumer staples index <.GSPS>, up 1.2 percent, led gains on the S&P 500.

Oil company Chevron Corp also was upgraded by Credit Suisse, and its shares rose 1.5 percent to $73.07.

Quadruple witching -- the expiration and settlement of four different types of September equity futures and options contracts -- created some market choppiness.

On a short-term basis, the market is due for a pause, but the underlying tone of the market and the economy is positive at present, said Michael Sheldon, chief market strategist at RDM Financial in Westport, Connecticut.

The Dow Jones industrial average <.DJI> was up 53.81 points, or 0.55 percent, at 9,837.73. The Standard & Poor's 500 Index <.SPX> was up 4.67 points, or 0.44 percent, at 1,070.16. The Nasdaq Composite Index <.IXIC> was up 10.21 points, or 0.48 percent, at 2,136.96.

The S&P was on track to finish more than 2 percent higher for the week, its second week of increases.

Among other broker upgrades, home builders Toll Brothers Inc and KB Home were both upgraded by J.P. Morgan Securities, which said the housing sector will continue to recover over the next 24 months and drive the current rally in home builders' stocks.

Toll shares rose 3.4 percent to $22.27, while KB Home's stock gained 3.4 percent to $20.36. The Dow Jones U.S. Home Construction index <.DJUSHB> jumped 1.7 percent.

(Editing by Kenneth Barry)

Credit Suisse Investment S&P