U.S. Steel retained its title as Western Pennsylvania's top performing company last year, beating out No. 2 H.J. Heinz and PNC Financial Services Group, the top performer two years ago.

		Top 50 rankings • See the rankings for this year's Top 50 in Business report. How we did it Figures for the Post-Gazette's Top 50 lists were derived from company reports and Post-Gazette research. Net income and revenue are for the latest fiscal year reported, in most cases calendar year 2008. Stock prices and price changes are for calendar year 2008, and market capitalization is based on shares outstanding and stock prices early this month. For overall rankings, an average score was determined for each of the seven performance categories: revenue, revenue change, net income, change in net income, stock price change, market capitalization and return on equity. The averages then were subtracted from individual company scores in each category, with the difference divided by the standard deviation for each of the categories to give each company a weighted score in each category. The weighted scores for each company in each category were then added up to determine the overall scores. An identical procedure was followed to arrive at the growth rankings, using the categories of revenue change, net income change, stock price change and return on equity.

Seven performance factors were used to determine the Post-Gazette Top 50's overall winner: revenue, revenue growth, net income, net income growth, stock performance, market capitalization (a measure of a company's worth determined by multiplying its share price by the number of shares outstanding), and return on equity, a gauge that measures how effectively management deploys capital provided by shareholders.

The formula used to rank the Top 50 favors large companies such as U.S. Steel, which was No. 1 in revenue and net income, No. 2 in net income growth and No. 3 in return on equity.

A few smaller companies managed to finish near the top, paced by No. 8 Calgon Carbon. The Robinson-based environmental products and services company, which ranked 18th based on market cap, benefitted from finishing first last year based on earnings growth.

Wabtec, which makes brakes, couplers and other components for the rail and mass transit markets, finished ninth overall. The Wilmerding company finished in the top 10 in two categories: return on equity and stock price performance. But it performed consistently in all categories over a year when most companies struggled with at least one aspect of their performance.

Consistency also was the key for No. 10 S&T Bancorp. The Indiana, Pa., bank, which ranked 24th based on market cap, placed in the top 10 in only one category -- it was the region's second-best performing stock last year. S&T ranked 40th overall the previous year.

In a year when many financial services companies took it on the chin, four other financial services companies besides PNC and S&T finished in the top 20 overall: WesBanco of Wheeling, First Commonwealth Financial of Indiana, Pa., ESB Financial of Ellwood City and Federated Investors, Downtown.

PNC and Federated were the financial industry's only representatives ranked 20th or higher the previous year.

Mylan also made a big jump in the rankings, moving from 22nd to sixth overall. The Cecil generic drug maker had the best performance based on revenue growth because of its acquisition of Merck KGaA's generic drug unit. Mylan also ranked sixth based on net income improvement, moving from a loss of $1.2 billion to a loss of $320 million last year.

The worst performer was newcomer Atlas Pipeline Partners. The Moon publicly traded limited partnership, which processes and distributes natural gas, finished last based on stock performance and net income growth.