Motorola ( MOT) announced a $1.2 billion accelerated stock repurchase Monday and set a new authorization to buy back up to $4.5 billion worth of additional shares over the next three years.

The accelerated repurchase closes out a $4 billion repurchase authorization announced in May 2005. Motorola will pay $1.2 billion to an unidentified intermediary and receive "a substantial majority" of the repurchased shares within three weeks. Final delivery of any additional shares is set for the first quarter of 2007.

"We have completed our first-ever share repurchase program almost two years ahead of schedule and we are immediately instituting a second share repurchase program," Motorola said. "We believe that at current price levels, Motorola shares are an attractive investment and our recent repurchases highlight our continuing confidence in Motorola's long-term growth. With our strong balance sheet and significant free cash flow, we maintain the flexibility to invest in our current business, take advantage of strategic opportunities, continue to repurchase our shares, pay dividends and further reduce debt."

Motorola has cash and equivalents of about $14.4 billion. At the current price, $4.5 billion would buy about 9% of its outstanding shares.

In premarket trading, Motorola shares rose 47 cents, or 2.3%, to $20.87.