The Standard & Poor’s 500 Index was up, then it was down, and is fighting to find its way in mid-day trading. The S&P 500 is up about 4.9% for the year, but down more than 2. 5% for the week as concerns about economic growth in the United States and debt problems in Europe continue.

Here are some of today’s best and worst S&P 500 performers.

Conoco Phillips (NYSE: COP) was higher on an announced split that had the shares up about $3.50, a gain of around 4.7% to over $77.87.  The refining division is being spun off to enhance shareholder value by allowing one segment to focus on “downstream” operations and the other on “upstream.”  Marathon Oil (NYSE: MRO) recently did such a transaction.

Consol Energy (NYSE: CNX) tacked higher by more than 4.8% to over $51.07, a gain greater than $2.35 a share.  Boosting its coal output guidance had Consol Energy among the day’s leaders.  It is trading above its 20 day, 50 day and 200 day moving averages.  With a relative strength index rating of 61.74, Consol is near the 70 ceiling, for when a stock is considered to be overbought.

Another energy company was also a top gainer, as Chesapeake Energy (NYSE:CHK) climbed higher by about 2.10%, up more than 60 cents to over $30.56.  Trading above its 20 day, 50 day and 200 day moving averages, Chesapeake Energy has a relative strength index rating of 60.78.

Hit hard in the morning session was the hospitality industry, with Marriott (NYSE:MAR) down by about 7% to under $34.32, a loss of more than $2.80 a share.  Marriott reported higher revenues and profits, but declining sales in its time share division, which is being spun off, to disappoint traders.  Marriott is trading below its 20 day, 50 day and 200 day moving averages.  With a relative strength index rating of 42, Marriott is close to the 30 floor for when a stock is considered oversold.

Host Hotels & Resorts (NYSE:HST) was also hit hard, off by about 3.80%, down about 66 cents to under $16. 60.  Host Hotels & Resorts is a very volatile stock, with a beta of 2.28.  It has a relative strength index of 46.13.  It is trading at less than its 20 day, 50 day and 200 day moving averages.

Starwood Hotels & Resorts (NYSE: HOT), down more than $1.84, was off by about 3.30% in the morning session.  Below its 20 day, 50 day, and 200 day moving averages, Starwood is another high beta stock, with a rating of 2.