Tesco has insisted a senior executive who sold shares in the business last week was unaware of the retailer's plans to issue a profit warning.

Bob Robbins, COO of Tesco's UK operations, sold 50,000 shares in the retailer at 404.51p on 4 January.

Yesterday (12 January), Tesco's shares closed at 323.4p after slumping 16% in the wake of the company's admission that continued falling UK sales would hit annual profits this year - and led to further investment in its domestic operations, which would weigh on earnings in its next financial year.

However, Tesco today insisted that Robbins was not involved in discussions over its new profit guidance or its plans to spend more money to revitalise its UK business.

Robbins, a Tesco spokesman said, sold the shares "for necessary family expenditure". 

The spokesman added: "The sale, which was not made within a close period, was approved in the usual way. We are confident that Bob was not in possession of any price-sensitive information at the time that the sale was approved. Tesco did not complete its Christmas trading period until after the sale was made.

"In fact, the significant movement in the share price on Thursday was, we believe, primarily due to the announcement on profit guidance and UK investment plans for 2012/13. Bob was not party to discussions around the profit guidance or the investment plans at the time he made his sale."