Adds details and background throughout, share move in paragraph 1 and last paragraph

July 1 (Reuters) - Britain's biggest fast-food chain Greggs GRG.L said on Wednesday that its Chief Financial Officer Richard Hutton will step down after 28 years with the company, sending its shares down 2.8% in early trade.

The baker has appointed Bakkavor veteran Ben Waldron as Hutton's successor, who will join the company on October 27 as CFO-designate and executive director, taking over the role from next January.

Hutton joined Greggs in 1998 after stints at KPMG and consumer goods giant Procter & Gamble PG.N, overseeing the company's finances as it transformed from a traditional bakery into a modern food-on-the-go brand.

His replacement, Waldron, brings deep experience in food manufacturing. He spent over 14 years at Bakkavor Group, a fresh-prepared food business, where he held a range of senior roles, including CFO and chief executive of Bakkavor's Asia and U.S. operations.

Greggs' sales rose 7.5% to £800 million in the first 19 weeks of the year, with like-for-like sales growth in company-managed shops of 2.5%, improving to 3.3% in the most recent 10 weeks, the company said in May.

Shares in the company fell 2.8% to 1,555 pence. They have fallen 4.8% so far this year.