Sweden's Annika Sorenstam edged into a one-shot lead of the ADT Tour Championship after shooting a two-under-par second-round 70.

Sorenstam, the joint overnight leader at the Trump International course in Palm Beach, Florida.

She reached seven under to head Australia's Rachel Teske (66), Canada's Lorie Kane (69), and American Meg Mallon (71).

Mallon, who also shared the first-round lead with Se Ri Pak, slipped back after dropping shots at the 16th and 17th, while Pak was on four under after a 73.

World number one Sorenstam is aiming to become the first player in 38 years to win 11 times on the LPGA Tour. She is also targeting a 13th worldwide victory this season.

"I've got nothing to lose and everything to gain this week," said Sorenstam, who won the Australian Masters and the Compaq Open on the European Tour.

"Whatever happens, I've had a great year. But I would love to win this week and make it 13 wins."

In third on five under was Australia's British Open winner and defending champion Karrie Webb, who fired a 70 to sit alongside American Rosie Jones (70).

Catriona Matthew (70) and fellow Scot Mhairi McKay lead the British contingent in a tie for 15th at one over.

McKay was four under through 15 before dropping five shots in the final three holes for a 72.

Meanwhile, Laura Davies carded a lacklustre 74 for three over and Janice Moodie was further back despite making amends for her opening 80 with a second-round 69, one of only four sub-70 scores.