In a day of frenetic transfer and contract activity, Manchester United, Chelsea and Arsenal all made significant announcements on Tuesday as they prepare for the weekend's start of the premier league season.

Like Grand National jockeys jostling for position on the start line, English soccer's heavyweights have been putting the final touches to their multinational squads before the transfer window closes at the end of August.

United, the defending champions who are already smiling after their Community Shield success over Arsenal on Sunday, led the way by signing two players.

The transfer of Brazil midfielder Kleberson from Atletico Paranaense for 5.93 million pounds ($9.49 million) had been on the cards for a while but went through after he was cleared for a work permit.

RONALDO SURPRISE

However, the 12.24 million-pound swoop for Portuguese teenage striker Cristiano Ronaldo from Sporting Lisbon was something of a surprise.

Both players signed five-year contracts and join Cameroon midfielder Eric Djemba Djemba, French striker David Bellion and U.S. goalkeeper Tim Howard as United's close-season recruits.

"We're delighted Kleberson is joining us because we've been chasing him for quite a few months," said United manager Alex Ferguson, whose team kick off at home to Bolton Wanderers on Saturday.

In 18-year-old Ronaldo, so named because he father was an admirer of former U.S. president Ronald Reagan, United have signed a player for the future who they see as the ideal understudy for Ruud van Nistelrooy.

The signings will revive the spirits of Ferguson who was furious when another Brazilian international, Ronaldinho, chose Barcelona ahead of the English club.

They will also placate fans wondering what would happen to the 40 million pounds generated by the sales of David Beckham and Juan Sebastian Veron.

MUTU SIGNS

Money is no object for Chelsea who took their summer spending to 74 million pounds with the acquisition of Romanian international striker Adrian Mutu from Parma.

The 24-year-old, who scored 18 goals in 30 Serie A games last season, has passed a medical and, subject to work permit clearance, could play in Sunday's league opener at Liverpool.

He joins Veron, Joe Cole, Damien Duff, Glen Johnson, Geremi Wayne Bridge in Chelsea's ever-growing squad and new owner Roman Abramovich says there is still more to come before the start of the season.

Cash-strapped Arsenal have no new players to rave about but the news on Tuesday that French midfield duo Patrick Vieira and Robert Pires had finally agreed new contracts was as good as any transfer.

Club captain Vieira, absolutely essential to Arsenal's hopes of regaining the title, had been holding out for months but finally signed a new contract taking him to the end of the 2006/7 season.

Pires, English player of the season in 2001/2002 when Arsenal won the league and FA Cup double, has extended his deal until the end of the 2005/6 season.

"I'm really confident about this season as we have a great squad here, with great team spirit and fantastic talent," said Vieira. "I really believe we'll go from strength to strength."

Arsenal's sole close-season purchase of note was German goalkeeper Jens Lehmann from Borussia Dortmund, a replacement for David Seaman who has left for Manchester City.

Arsenal start their campaign at home to Everton on Saturday.