Wabash National Corp. senior VP Derek Nagle said he plans to retire by the end of the year. Nagel, who also serves as president of Wabash's North American Trailer Centers subsidiary, joined the company when it purchased rival Fruehauf Trailer Corp. in 1997. The news comes at a tough time for Lafayette, IN-based Wabash. The trailer manufacturer lost $232.2 million last year -- with almost half of those losses in the fourth quarter alone -- as its sales fell over 33%. However, Wabash noted in February that booked $100 million worth of trailer orders for 2002 -- largely because several large trucking customers had better than expected financial results this year.