Manchester City hope £38m Sergio Aguero will keep United quiet

'Noisy neighbours' make statement to arch-rivals as Argentina striker tweets 'Happy to be at this club'

Manchester City are expected to announce the biggest deal of the summer today, after their £38m capture of Sergio Aguero from Atletico Madrid was confirmed by the Argentine striker on Twitter last night.

Having sat back and watched as their neighbours United spent £50m on Ashley Young, Phil Jones and David de Gea, City's chairman Khaldoon al-Mubarak took direct control of negotiations with Atletico to sanction the deal. Aguero, 23, cut short a holiday to his homeland and flew from Madrid to Manchester yesterday before undergoing a medical at the Bridgewater Hospital.

"Now I am a City player," Aguero wrote on Twitter last night. "Happy to be at this club and in this city. Thank you to everyone for the welcome and the reception." There is a strong possibility that he could make his City debut as soon as Sunday, when Roberto Mancini's side take on Internazionale in Dublin in a friendly.

Aguero will be become the biggest transfer in the club's history, eclipsing the £32.5m spent to take Robinho from Real Madrid in 2008, and is the second most expensive player in British football history, after Fernando Torres who cost £50m when he moved from Liverpool to Chelsea in January. Aguero has been offered a five-year deal worth £44m, which works out at wages of £170,000 a week.

The recruitment of Aguero, who scored 27 goals in a struggling Atletico side last season, will take City's summer spending to £51m, following the arrivals of Gaël Clichy from Arsenal for £7m and Stefan Savic from Partizan Belgrade for £6m. The Argentine striker leaves Madrid with an admirable record of 102 goals in 234 appearances.

Aguero's arrival will also add some consolation to City fans over the expected sale of Carlos Tevez, who is still determined to leave despite the recent collapse of his proposed transfer to Corinthians. Inter seems the most likely destination for Tevez, who met with the club's sporting director Marco Branca while on holiday in Sardinia last week. Inter are understood to be keen to take Tevez on loan for a season, before making the transfer permanent in a year's time.

Meanwhile, midfielder Michael Johnson, who has hardly featured for City in the last three years because of injury, is on the point of joining Leicester City, managed by ex-City manager Sven Goran Eriksson, on loan