Ralph Lauren Corp. is reporting a 35 per cent increase in fourth-quarter profit, but economic challenges and certain strategic initiatives have cut into sales. The New York-based company is reporting net income of $US127.2 million ($A131.94 million), or $US1.37 per share, for the three months that ended on March 30. That compares with $US94.4 million, or 99 cents US per share, a year earlier. Revenue rose a slim 1.2 per cent to $US1.64 billion. Analysts had expected earnings of $US1.31 per share