Tevez (left) and Mascherano have been linked with the top clubs in Europe

Striker Tevez, 22, and midfielder Mascherano, 22, join the Hammers from Brazilian side Corinthians on permanent deals for undisclosed fees.

The pair have been linked with moves to Manchester United, Arsenal and Chelsea.

But the Hammers are reported to have struck a deal with Media Sports Investments, who own the rights to the two players.

According to reports MSI were headed until June by Kia Joorabchian, who resigned but retained an investment in the two Argentines.

MSI were linked with a takeover of West Ham last season but eventually pulled out.

The club said: "West Ham United are delighted to announce the double signing of Argentinian World Cup stars Carlos Tevez and Javier Mascherano from Brazilian club Corinthians.

606 VIEW A fantastic pair of signings and possibly the dawn of a new era

DH

"The pair have been signed for an undisclosed fee and put pen-to-paper on permanent contracts with the club this afternoon. All other aspects of the transfers will remain confidential and undisclosed.

"The transfers represent a massive coup for the Hammers, who have beaten off some of Europe's biggest clubs to secure the services of the duo."

Tevez has emerged as one the most highly rated young strikers in the world since signing for Corinthians from Boca Juniors for £9.5m in December 2004.

He has been strongly linked with Chelsea this summer, with a transfer fee of between £20m and £60m being reported.

In May, Joorabchian, then president of London-based MSI, said: "Tevez will leave Corinthians if a team pays the contract's release clause, which is between £69m and £83m."

Both Tevez and Mascherano returned to Argentina's squad for Sunday's friendly against Brazil at Arsenal's Emirates Stadium after signings their deals.