JOHANNESBURG (Reuters) - South Africa's biggest private hospital group Mediclinic International reported a sharp slowdown in earnings growth on Thursday as regulations squeezed the profit margin of its Swiss unit. The company reported a 9 percent rise in full-year earnings, compared with 46 percent growth the previous year, sending its shares lower. Mediclinic said its Hirslanden unit, the largest private hospital network in Switzerland, was hit by an adjustment of the national outpatient tariff by the Swiss government. The adjustment diverted funds away from specialised services, such as radiology, and channelled it towards primary care. The changes, which the company calls a "one-off thing", lowered profits in Switzerland by 5 million Swiss francs ($5.4 million), Mediclinic CEO Danie Meintjes said in a conference call. The company's normalised diluted headline earnings per share rose to 400.6 cents for the year ended March from 367.8 cents a year earlier. Headline EPS is the main profit gauge in South Africa that strips out certain one-off items. "Expectations were quite high and 9 percent growth was on the lower end of the revised guidance," said Investec Asset Management's Clyde Rossouw from Cape Town. "South African hospitals are still outperforming Life and Netcare," said Rossouw. Shares in Mediclinic, which also operates in the Middle East, were down 6.3 percent at 113.05 rand by 1230 GMT, compared with a 0.3 percent fall in the blue-chip JSE Top-40 index. Revenue for the latest financial year rose 16 percent to 35.2 billion rand ($3 billion), Mediclinic said. The final dividend increased by nearly 11 percent to 106.5 cents a share, the firm said. ($1 = 11.8244 rand) ($1 = 0.9339 Swiss francs)