Wal-Mart will start selling Apple’s popular iPhone on Sunday, the chain said, confirming earlier reports by employees.Bentonville-based Wal-Mart Stores Inc. will become the second independent retail chain after Best Buy Inc. to sell the phone. It is also sold at Apple Inc. and AT&T Inc. stores. Wal-Mart will sell the phones for $2 less than the regular price with a two-year contract: $197 for the 8-gigabyte model, or $297 for the 16-gigabyte model. Best Buy is discounting the phone by $9. Reports that Wal-Mart would sell the phone, but not the exact launch date or the terms, surfaced early this month through store employees who had been briefed.