World number one Annika Sorenstam shot a course record six-under 66 to lead at 11 under after the second round of the Compaq Open at Vasatorp in Sweden.

The home favourite has a four-shot advantage over compatriot Sophie Gustafson, the first-round co-leader, who birdied the last from 35 feet for a 70.

Germany's Elisabeth Esterl, who had a 67 for the second-best score of the day, shared third at six under with Nadina Taylor of Australia and Johanna Head of Great Britain.

Head fired a 70 but was disappointed that she had not finished even closer to the top.

"I could have been eight or nine under," claimed the Surrey 29-year-old, who is seeking her first win on the European Tour.

"I was hitting the ball great but just couldn't get confident with the putter."

In fact, the Briton missed a six-foot birdie putt at the last to miss out on a chance of a share of second place.

Despite her record-breaking round, Sorenstam, aiming for a record third win in the tournament, went straight to practice with her Swedish coach Henri Reis.

"There were a couple of details that we fixed," said the Swede, who is eager to make up for last week's British Open flop where she missed her first cut in 75 LPGA events.

"It worked fine on the range, but it's not certain it will work on the course tomorrow."

Reis said the world's top-ranked women's golfer is playing at 70-75%.

"She'd shoot a 62 if she was 100%," Reis said of Sorenstam, who carded a record 59 in an LPGA event last year.

Former US Open champion Laura Davies of England, eighth on the list, finished on three under after a 71, a round highlighted by a run of three birdies in a row from the 11th.

Selected second round scores from the Ladies European Tour, Compaq Open, Vasatorp, Sweden (Gbr and Irl unless stated):

-11 Annika Sorenstam (Swe) 67 66
-7 Sophie Gustafson (Swe) 67 70
-6 Nadina Taylor (Aus) 70 68, Elisabeth Esterl (Ger) 71 67, Johanna Head 68 70
-5Suzann Pettersen (Nor) 71 68
-4 Liselotte Neumann (Swe) 69 71
-3 Laura Davies 70 71, Catrin Nilsmark (Swe) 70 71, Joanne Mills (Aus) 70 71