NEW YORK (AP) — Schering-Plough Corp. Chief Executive Fred Hassan’s compensation slipped 34 percent in 2008, mainly due to a decline in stock-based awards as the company’s share price fell, according to an Associated Press analysis of data filed with regulators Monday. Schering-Plough, which is being bought by Merck & Co., paid Hassan $16.2 million in 2008, down from $24.7 million in 2007. His salary rose 3 percent to just over $1.7 million. His performance bonus fell 16 percent to just under $3.4 million. Perks, including company contributions to savings and use of the corporate jet, rose just under 2 percent to $620,266. The bulk of Hassan’s compensation again came in the form of stock and options valued at $10.5 million when they were granted. The year before, he received similar awards granted at $18.4 million when they were granted. The Associated Press formula is designed to isolate the value the company’s board placed on the executive’s total compensation package during the last fiscal year. It includes salary, bonus, performance-related bonuses, perks, above-market returns on deferred compensation and the estimated value of stock options and awards granted during the year. The calculations don’t include changes in the present value of pension benefits, and they sometimes differ from the totals companies list in the summary compensation table of proxy statements filed with the Securities and Exchange Commission, which reflect the size of the accounting charge taken for the executive’s compensation in the previous fiscal year. Shares fell 36 percent during the year though the company swung to a profit of $1.65 billion, or $1.01 per share. Sales rose 46 percent to $18.5 billion. The $41.1 billion acquisition of the Kenilworth, N.J.-based company by Merck is expected to close during the fourth quarter. The companies are partners on the cholesterol drugs Vytorin and Zetia. U.S. sales have been falling since the companies reported a study showing pricey Vytorin controls plaque buildup in arteries no better than generic Zocor. Vytorin combines Zetia and Zocor.