Motorola ( MOT) plans to pay down some of its debt to the tune of $1.7 billion.The chip and communications equipment maker announced on Monday that it plans to repurchase two sets of notes. The company said it plans to redeem one set, which has a principal amount of $1.4 billion, and has issued a tender offer for the second, which has a principal amount of $300 million. The larger set of notes is due in 2006 and carries a set rate of 6.75%. Motorola plans to redeem all of the notes in the set at a price to be determined on Aug. 23. The second set of notes is due in 2007, with a rate of 7.6%. The Schaumberg, Ill.-based company has offered to repurchase some or all of the notes depending on the response to the tender offer, which closes on Aug. 5. As of April 4, Motorola had about $6.7 billion in long-term debt. The company's announcement came after the close of regular trading. In after-hours exchanges, Motorola shares fell 15 cents, or 1%, to $15.27. Earlier in the day, the company's stock gained 14 cents, or 0.9%, to close at $15.42.