* FTSEurofirst 300 retreats from near 14-year highs
* Casino falls after slower sales growth
* Pearson leads media stocks lower
By Atul Prakash
LONDON, April 16 (Reuters) - European equities retreated from 14-year highs on Thursday, led lower by shares in French retailer Casino, which reported slower sales growth, and Pearson, on a report that one of its educational technology projects was in trouble.
Casino's stock dropped 4.6 percent after Societe Generale and Natixis cut their target prices, and Pearson fell 4 percent on a report the Los Angeles Unified School District was seeking a refund from Apple over a bungled $1.3 billion iPad plan with a curriculum from Pearson.
The pan-European FTSEurofirst 300 index closed 0.9 percent lower at 1,635.76 points after gaining 0.6 percent on Wednesday to reach levels not seen since late 2000.
Germany's DAX, down 1.9 percent, underperformed the wider market, after a recent sharp rally and as the euro gained against the dollar. A stronger local currency is generally seen negative for export-oriented companies.
The DAX index rose 22 percent in the first quarter, against a 15-percent gain for the wider stock market.
"The DAX is just taking a breather after a stellar run on the back of a depressed euro, ultra-low interest rates and the quantitative easing programme," B Capital Wealth Management managing director, Lorne Baring, said.
"Valuations are still reasonable and we see a 10 percent upside for the index in the next six months," he said.
Greece was still a risk factor for European stock markets, he said.
Greece's benchmark ATG share index fell earlier in the day on a Financial Times report saying the International Monetary Fund had rebuffed a request from the country to delay loan repayments. Greece later denied the report.
The ATG rose 1.1 percent after Prime Minister Alexis Tsipras told Reuters he was "firmly optimistic" his government would reach an agreement with foreign creditors by the end of April despite friction over issues such as pension and labour reform.
Among standout losers, Diageo, the world's largest spirits maker, fell 3.6 percent after saying net sales in the three months to March 31, the third quarter of its financial year, fell 0.7 percent.
Mid-cap British utility company Telecom Plus sank nearly 20 percent after saying it would write down about 11 million pounds of unrecoverable bills at its gas unit and that it expected full-year pretax profit to be "significantly below market expectations".
Bucking the trend, Unilever rose 2.4 percent after reporting better-than-expected sales for the first quarter. (Additional reporting by Blaise Robinson in Paris; Editing by Louise Ireland)