Following heavy overnight rain, the start was delayed until 1.55pm. Early on, Durham had a chance to unseat Ayling when he was on 20, however Wayne Larkins dropped him at slip off Simon Hughes.
Ayling's previous highest Championship score was 88 against Lancashire at Liverpool in 1988. Middleton's hundred was his fifth in the Championship this season, taking five hours off 272 balls before rain ended play 11 overs early.
Shoaib Mohammad, the Pakistani captain, also had the weather to contend with. Resuming on 57 after a rain-delayed start he garnered a century against a World XI side at the Scarborough Festival. Shoaib was 105 not out when he declared at 263 for 6 at tea.
Leicestershire have been unable to sell almost 1,000 of the 4,500 tickets allocated to them for next week's NatWest final at Lord's. The tickets were priced from pounds 18 to pounds 35. Although the cheaper tickets were sold, the club has found it difficult to persuade people to buy the pounds 35 tickets and has had to return most of them.Reuse content