Jan. 23 (Bloomberg) -- Patrick Cescau, the former chief executive officer of Unilever, became the third Tesco Plc director to buy shares in the U.K.’s biggest supermarket owner since the grocer trimmed profit estimates this month.

Cescau, who became a non-executive director of Tesco in February 2009, purchased 18,340 shares on Jan. 20, the Cheshunt, England-based company said today in a statement. Fellow non- executive Ken Hydon bought 30,000 shares last week, while Chairman Richard Broadbent acquired 30,149 on Jan. 12.

Tesco shares fell the most since at least 1988 on Jan. 12 after the retailer said full-year profit will be at the “low end” of estimates, while next year will see “minimal” growth in earnings. The announcement raised concern that competitors will continue to eat into the company’s 30 percent share of the U.K. grocery market with promotions and fresh food offers.

Moody’s Investors Service said Jan. 20 it has begun reviewing whether to downgrade Tesco’s A3 long-term senior unsecured rating. The retailer has had the fourth-lowest investment-grade rating at Moody’s since July 30, 2008.

--Editors: Robert Valpuesta, Thomas Mulier.

To contact the reporter on this story: Paul Jarvis in London at pjarvis@bloomberg.net

To contact the editor responsible for this story: Sara Marley at smarley1@bloomberg.net